Junior researchers frequently wonder how many references should be included in their research papers. The common response? “As many as you need.” What exactly does that mean? While we admit there are very few hard-set rules regarding this issue, in this article, we will try to provide more concrete guidelines that will help you assess whether you have enough references in your paper.
Before we do so, let us briefly explain why references matter and whether the number of references you include can project certain perceptions about the quality of your work. There is such a thing as having too many or too few.
Why references are necessary
References show that you have carefully reviewed the relevant literature and are now contributing something novel to the academic community. You establish authority and credibility when you can critically assess other literature and distinguish your findings from previous works (if any exist). We emphasize “critically assess” in the last sentence because references are only as good as you apply them to your research. Therefore, the famous adage “quality over quantity” is the key to deciding how many references are sufficient.
Quantity can matter due to perceptions
We would be remiss if we didn’t tell you that being at either extreme (having too few or too many references) can reflect poorly on your intellectual aptitude and your study’s validity. Here’s why.
- If you don’t have enough references, particularly on a topic familiar to a wide audience, readers may think that you haven’t done enough research into existing literature. Surely someone else has thought about related topics or used similar techniques. If you’re sloppy in conducting your diligence, readers will wonder whether your paper is worth reading. What’s novel and valuable about your paper? Were you just as sloppy with conducting your study? The answers to these questions need to be evident. Additionally, readers might be concerned that you may have plagiarized by failing to properly cite information. Unless you’re John Nash, who cited only two texts in his seminal 26-page PhD thesis (one of which was to his prior work), ensure that you’ve properly researched the relevant papers and included appropriate citations!
- If you have too many references, readers may wonder if you did any original research at all. Unless you’re writing a literature review, your paper’s primary focus should be on your investigation and findings. Don’t bury your hard work under strings of citations and discussion regarding other works. Show your readers what you’ve discovered and how the new information you present fits into or departs from the academic community’s current understanding of your topic.
Additionally, let us highlight the difference between the number of references versus citations. References are the source materials; therefore, each reference should be listed only once in your references section. Citations are meant to identify the source of the information you use in your paper. You can cite a reference multiple times. Therefore, the number of citations you have is typically larger than the number of references. The opposite situation should never happen!
Key factors influencing the number of references you use
The following are some of the many factors that may influence the number of references you use:
- The number of references required for a paper will depend largely on your work’s purpose. For example, literature and systematic reviews are surveys of existing studies. Therefore, their reference lists will be more exhaustive than those of research papers whose primary focus is the current authors’ findings. Indeed, if you examine many journals’ author guidelines, you’ll note that journals have a higher maximum reference limit for review articles than original research papers.
- The length of your reference list will also depend on your researchpaper’s subject matter. For example, if you are writing about a less studied field, such as a subfield of neuroparasitology, you may discover that there aren’t many papers to cite. Similarly, newer fields will have fewer published papers that can be referenced. If you find yourself in this situation, review the references used by relevant current literature and see if you can expand your research, and thus your reference list, with valuable content from there.
- Another factor will be your institution or journal’s requirements. If you are preparing a dissertation or thesis, double-check your department’s requirements. While rare, they may have specific limits. More commonly, journals restrict the number of references due to printing constraints.
- It may happen that you don’t have access to certain literature that could have served as a reference. In such a situation, you may wish to look for an institution that may be able to provide you access to that literature for the purposes of reviewing the content.
- Given that more papers are being published than ever before in most fields, it is likely that reference lists will grow longer simply because there are more data points and discussions available to cite. Keep track of changes to the size of reference lists in publications related to your field.
- Finally, a paper’s length bears some correlation to the number of references.
The “right” number of references
Below, we provide tips on how to decide if you have enough resources. We also provide some general reminders on how to effectively use references. After all, references are meant to enhance your paper while still maintaining your research as the focal point.
Let journals be your guides
- One way to gauge how many references you should have is to survey academic journals for your article type in your field. Review their author guidelines for limits on the number of references for your article type, and make sure your reference list complies with those journal restrictions.
- Read recent articles relevant to your topic; check how many references other authors have included in their papers for the same article type as yours, and how frequently those works were cited per page.
- Keep in mind that the above methods will give you an estimate of how many references you should include but will not tell you how many citations you’ll need per page. The latter is impossible to state simply because certain sections may have no citations at all (the results section, for example).
Statistics regarding the number of references and citations
To give you a general idea, the following are some estimates from a couple of studies that examined the citation characteristics of articles published in various disciplines.
According to Milojević’s study encompassing research in the fields of astronomy, mathematics, robotics, ecology, and economics, the highest and average number of references per article page were as follows:
- Ecology: highest, ~58; average reference per page, 6;
- Math and robotics: highest, ~28; average reference per page, <1; and
- Economics: highest, ~ 32; average reference per page, >1 but <2.
The above findings were based on data compiled from the first 20 years of the author’s research. Since then some fields have increased the number of references. Thus, make sure to examine your target journal’s most recent and relevant publications for a better idea of how many references to include based on the specific type of article you plan to write.
In another study by Falagas et al. (2013), medical journals averaged 29 references for articles that were 7.88 pages long (as printed in journals).
Finally, although the sample size was small (63 journals), Gali Halevi observed the following citation trends of a broader range of disciplines.
- The average number of references per article was the highest for the social sciences, physics, and astronomy, and arts & humanities (roughly 54 references per article).
- On the other hand, health professions and earth and planetary sciences had the fewest references per article at an average of 8 and 17 references, respectively.
- Math and engineering averaged at roughly 29 references per article.
- Biochemistry, genetics and molecular and other biological sciences averaged at 51.
- Hard and natural sciences more frequently cited recent literature while social sciences and math were likely to include older sources.
Note that the Halevi study is limited in size, fails to factor in article type and does little to account for variances across different fields and journals. For example, it is possible that more review articles could have been reviewed for certain fields than others. With that said, we provide the above information to provide a rough estimate.
At the end of the day, please keep in mind the requirements of your institution or target journal and the general trends for your specific article type (by examining the most recent relevant publications).
For additional information regarding journal restrictions on the number of references, click here.
Some dos and don’ts of using references
- Don’t repeat references within a reference list.
- Don’t repeatedly cite yourself. Make sure to balance your discussion with external literature citations.
- Be careful about citing old references. The rule of thumb is to go back at most five to six years. Exceptions to this rule should be reserved for “seminal” works relevant to explaining what prompted your research. Roughly 85% of all cited works should be less than five years old.
- Be careful not to cite several references in one place without discussing the relevance of each work to your research. In other words, don’t say, “We referred to previous studies in this field (1-7)” unless you later explain how each of reference #s 1-7 apply to your discussion.
- Confirm the quality of the work you cite. Are there any ethical issues regarding the paper that would disqualify it as a good source? Do your references come from reputable sources such as respected journals rather than random blogs and website links? Remember that your analysis is only as good as the verifiable information you use to conduct your research.
- One of the main purposes of citing existing literature is to show the “knowledge gap” regarding your topic. Therefore, make sure the works you reference naturally lead readers to wonder about the research question you address in your paper. To explain further, think about your favorite fictional story. A successfully written story only reveals the background information needed for the reader to follow along in the story. You’ll rarely see an author waste time writing about how the main character stubbed his toe one day while going to work unless that event relates to an important aspect of the story. Similarly, the references you cite should support the story building you create in your research paper.
- Don’t completely ignore the paper that could disprove your hypothesis. You want to show objectivity and that you took a balanced and unbiased approach to conducting your research. Mention the potentially conflicting evidence and explain why you believe it is flawed or inapplicable to your research.
- In qualitative research papers, you may have fewer references.
- Anything you cite in your paper should be listed in the references section. Anything listed as a reference should have been quoted or paraphrased in the text. If either rule is violated, something is wrong.
- Finally, remember that a paper will typically have more citations in the Introduction and Discussion sections than in other parts.
- Stefanie Haustein. Chapter 2 of Multidimensional Journal Evaluation: Analyzing Scientific Periodicals Beyond the Impact Factor. (De Gruyter Saur, 2012).
- Gali Halevi, “Citation characteristics in the Arts & Humanities.” [Note this paper involved a limited sample size and did not factor in article type.]
- Staša Milojević, “How are academic age, productivity and collaboration related to citing behavior of researchers?”
- Falagas, Matthew E., Zarkali, Angeliki, Karageorgopoulos, Drosos E., Bardakas, Vangelis, and Mavros, Michael N., “The Impact of Article Length on the Number of Future Citations: A Bibliometric Analysis of General Medicine Journals.”
There's nothing like an approaching deadline to give you the motivation (and fear) you need to get writing – don't stress though, we're here to help you out!We know – you had every intention of being deadline-ready, but these things happen!
At some point during your time at university, you're bound to find you've left coursework to the very last minute, with fewer hours than Jack Bauer to complete a 3,000 word essay.
But don't sweat, cause 3,000 words in a day is totally doable! Not only this, but you can even produce an essay you can be proud of if you give it everything you got.
Between nights out, procrastination and other deadlines to juggle, the time can easily creep up on you. However, the worst thing you can do in this situation is panic, so keep calm, mop up the cold sweats and read on to find out how to nail that essay in unbelievable time!
Just to clarify – we're certainly not encouraging anyone to leave it all to the last minute, but if you do happen to find yourself in a pickle, you're going to need some help – and we're the guys for the job.
Are you a procrastination master? Check out these 13 hacks that will do wonders for your productivity levels, or these apps to help streamline your life!
Credit: Dimitris Kalogeropoylos – Flickr
Fail to plan and you plan to fail – or so our lecturers keep telling us. Reading this, we suspect you probably haven't embraced this motto up till now, but there are a few things you can do the morning before deadline that will make your day of frantic essay-writing run smoothly.
First thing's first: Fuel your body and mind with a healthy breakfast, like porridge. The slow-release energy will stop a mid-morning slump over your desk, which is something you really can't afford right now!
Not in the mood for porridge? Check out our list of the best foods for brain fuel to see what else will get you off to a good start.
Pick your work station
Choose a quiet area where you know you won't be disturbed. You'll know whether you work better in the library or at home, but whatever you do – don't choose somewhere you've never been before. You need to be confident that you'll be comfortable and able to focus for as long as possible.
Be organised and come equipped with two pens (no nipping to the shop because you ran out of ink), bottled water, any notes you have, and some snacks to use as mini-rewards. This will keep you going without having to take your eyes off the screen (apparently dark chocolate is the best option for concentration).
Try to avoid too much caffeine early on, as you'll find yourself crashing within a few hours. This includes energy drinks, by the way!
Shut out the world
Procrastination is every student's forte, so turn off your phone (or at least switch notifications off) and refrain from checking Facebook, Twitter, Snapchat, or any other social media channels you're addicted to. We mean it!
A good tip is to get a friend to change your Facebook password for you for 24 hours and make them promise not to tell you it, even if you beg (choose a friend that enjoys watching you squirm). Otherwise, you can also temporarily deactivate your account.
Set yourself goals
Time management is of utmost importance when you have 24 hours before deadline. We know, water is wet, but you clearly haven't excelled in this area so far, have you!
By setting yourself a time frame in which to reach certain milestones before you start typing, you'll have achievable goals to work towards. This is a great method of working, as it makes the prospect of conjuring up 3,000 words from thin air much less daunting if you consider the time in small blocks.
Let's say it's 9am and your essay is due in first thing tomorrow morning. Here's a feasible timeline that you can follow:
- 9:00 – 9:30 – Have your essay question chosen and argument ready
- 9:30 – 9:45 – Break/ snack
- 10:00 – 12:00 – Write a full outline/plan of your essay
- 12:00 – 13:00 – Write your introduction
- 13:00 – 14:00 – Take a break and grab some lunch (you deserve it)
- 14:00 – 16:00 – Get back to your desk and do all your research on quotes etc. that will back up your argument
- 16:00 – 20:30 – Write all of your content (with a dinner break somewhere in the middle)
- 20:30 – 22:30 – Edit and improve – extremely important step, so take time with this
- 22:30 – 23:00 – Print and prepare ready for the morning
- 23:00 – (morning) – If you've not finished by this point, don't worry – completing in time is still possible. Just make sure you've eaten well and have enough energy to last you until the early hours of the morning.
Also remember to schedule in a few breaks – you need to spend the whole 24 hours productively, and you can't be on form for a full day without short breaks to rest your eyes (and your brain!).
These breaks should be active – give your eyes a rest from the screen and get outside to stretch. We recommend a ten minute break at least every 1.5 hours.
Choosing a question and approach
Time: 9am – 12pm
If you've been given a choice of essay questions, you should choose the one you feel most strongly about, or have the most knowledge about (i.e the topics you actually went to the lectures for!).
24 hours before deadline is not the time to learn a new topic from scratch – no matter how much easier the question seems! Also, beware of questions that seem easy at first glance, as often you'll find that the shorter questions or the ones using the most straight-forward language can be the hardest ones to tackle.
Next, decide your approach. How are you going to tackle the question? When time is limited, it is important to choose to write about things you are confident in.
Remember that it's your essay and as long as you relate your argument to the question and construct a clear, well supported argument, you can take it in any direction you choose. Use this to your advantage!
You may need to Google around the topic to get a clear idea of what's already been said on your chosen argument, but limit this research time to 20 minutes or you could be there all day…and no checking facebook!
Now, type out 3-5 key points that you'll aim to tackle in your argument, and underneath these use bullet points to list all the information and opinions, supporting arguments or quotes you have for each point. Start with the most obvious argument, as this will provide something to link your other points back to – the key to a good essay.
Once you've done this, you'll now find you have a detailed outline of the body of your essay, and it'll be a matter of filling in between the lines of each bullet point. This method is perfect for writing against the clock, as it ensures you stay focused on your question and argument without going off in any tangents.
Nailing that introduction
Credit: Steve Czajka – Flickr
Time: 12pm – 1pm
Sometimes the introduction can be the most difficult part to write, but that's because it's also the most important part!
Don't worry too much about making it sound amazing at this point – just get stuck into introducing your argument in response to your chosen question and telling the reader how you will support it. You can go back and make yourself sound smarter later on when you're at the editing stage.
Create something of a mini-outline in your introduction so you signpost exactly what it is you're planning to argue. Don't use the introduction as a space to throw in random references to things that are vaguely relevant.
When in doubt, leave it out!
Doing your research
Credit: Photo Monkey
Time: 1pm – 4pm
Now it's time to gather outside information and quotes to support your arguments.
It's important to limit the time you spend on this, as it is easy to get distracted when Google presents you with copious amounts of irrelevant information. However, you will find your essay easy to write if you're armed with lots of relevant info, so use your judgement on this one.
Choose search keywords wisely and copy and paste key ideas and quotes into a separate ‘Research' document. If using reference books rather than online, give yourself ten minutes to get anything that looks useful from the library, skip to chapters that look relevant and remember to use the index!
Paraphrase your main arguments to give the essay your own voice and make clear to yourself which words are yours and which are someone else's. Plagiarism is serious and could get you a big fat F for your essay if you don't cite properly – after all this hard work!
Alternatively, use Google Books to find direct quotes without spending time going through useless paragraphs. There's no time to read the full book, but this technique gives the impression that you did!
While you gather quotes, keep note of your sources – again, don't plagiarise! Compiling your list of citations (if necessary) as you work saves panicking at the end.
Extra referencing tips!
Take quotes by other authors included in the book you're reading. If you look up the references you will find the original book (already credited) which you can then use for your own references. This way it looks like you have read more books than you have, too. Sneaky!
Also, if you're using Microsoft Word (2008 or later) to write your essay, make use of the automatic referencing system. Simply enter the details of sources as you go along, and it will automatically create a perfect bibliography or works cited page at the end. This tool is AMAZING and could save you a lot of extra work typing out your references and bibliography.
Bashing those words out
Credit: Rainer Stropek – Flickr
Time: 4pm – 8.30pm
Get typing! Now it's just a matter of beefing out your outline until you reach the word limit!
Get all your content down and don't worry too much about writing style. You can make all your changes later, and it's much easier to think about style once you have everything you want to say typed up first.
More ideas could occur to you as you go along, so jot these ideas down on a notepad – they could come in handy if you need to make up the word count later!
Use the research you gathered earlier to support the key ideas you set out in your outline in a concise way until you have reached around 2,500(ish) words.
If you're struggling to reach the word limit, don't panic. Pick out a single point in your argument that you feel hasn't been fully built upon and head back to your research. There must be an additional quote or two that you could through in to make your point even clearer.
Imagine your essay is a bit like a kebab stick: The meat is your essential points and you build on them and build around each piece of meat with vegetables (quotes or remarks) to make the full kebab… time for a dinner break?
Editing to perfection
Time: 8.30pm – 10.30pm
Ensure that all the points you wanted to explore are on paper (or screen) and explained fully. Are all your facts correct? Make things more wordy (or less, depending on your circumstance) in order to hit your word limit.
You should also check that your essay flows nicely. Are your paragraphs linked? Does it all make sense? Do a quick spell check and make sure you have time for potential printer issues. We've all been there!
A lot of students overlook the importance of spelling and grammar. It differs from uni to uni, subject to subject and tutor to tutor, but generally your writing style, spelling and grammar can account for up to 10-20% of your grade. Make sure you edit properly!
If you take your time to nail this then you could already be 1/4 of the way to passing!
Time to get started…
While completing essays 24 hours before the deadline is far from recommended and unlikely to get you the best grades you've ever gotten (try our top tips for getting a first if that's your goal), this guide should at least prevent tears in the library (been there) and the need for any extensions. Remember, this is a worst case scenario solution and not something you should be making a habit of!
Now, why are you still reading? We all know you've got work to do! Good luck!
Exams coming up? Check out our guide on how to revise in one day too. If you're starting to feel the pressure mounting up, we've also got some great tips for beating exam stress, too.
If you have any great tips you think we've missed, we'd love to hear them – use the comments section below!