You truly are navigating a maze when it comes to citations and the question of how to write references in research papers. In part 1 of this article, we touched upon citations, which are pointers embedded in the text of a research paper, to sources of information or to other research relevant to that being described in the research paper. Those pointers lead to references in research papers, which typically appear at the end of the text. Whereas citations merely point us to sources in research papers, references describe those sources in sufficient detail for readers (1) to know the title of each source, who is responsible for its content, and when it was published; (2) to look up those sources; and (3) to obtain the documents in question if required.
Types of references in research papers
In writing a research paper, a researcher draws upon many sources of information, knowledge, opinions, and so on. One of the the most common types of references in research papers is other research papers published in journals; other common sources include technical reports, handbooks, presentations at conferences, and books. Increasingly, the sources in research papers are digital and include web pages, databases, blog posts, and even tweets and emails.
Not all sources are considered equally credible, and some may not be accessible to all because they are behind paywalls or available only to members of a network (company intranets, for example) or because they are personal exchanges.
How to write references in research papers
If the citations follow the Harvard system, references in a research papers are sorted alphabetically by the last name of the first author; if the citations follow the Vancouver system, the references are arranged by numbers: the reference corresponding to the first numbered citation is numbered 1, and so on. If a source is cited again, its allocated number does not change.
Some additional conventions govern the alphabetic sorting of references in research papers. For instance, when authors have some papers in which they are the only author and others in which they have one or more co-authors or when the same author or authors have papers published in different years or even within the same year.
Some publishers make even greater demands of references in research papers: authors are expected to sort the list of references alphabetically, as in the Harvard system; then number the sorted list serially; and then renumber all the citations within the text so that each corresponds to its new number!
How to add references in a research paper: Key elements
For a source of information to be described accurately, some minimum details are required. Here’s one example of writing references in research papers – ‘Nature 171: 737’ is a code that, if you know how to decipher it, tells you that it means an article published in Nature (a weekly journal published from the UK) that begins on page 737 of volume 171 of that journal. However, it does not tell you what the article was about, who wrote it, when it was published, or even how long it is. A complete reference in research papers (Fig. 1), however, tells you that the title of the article was ‘Molecular structure of nucleic acids: a structure for deoxyribose nucleic acid’, that it was written by J. D. Watson and F. H. C. Crick, that it was published in 1953, and that it ran to no more than two pages.
| Watson J D and Crick F H C. 1953. Molecular structure of nucleic acids: a structure for deoxyribose nucleic acid. Nature 171: 737–738
Fig. 1 A typical reference to a paper published in a journal |
When thinking about how to write research references, remember that the elements that make up a reference to an article published in a journal are different from those that make up a reference to a book (edition if not the first, the publisher, and the place of publication, although the last is no longer considered essential in today’s globalized publishing). The elements that make up a reference to a technical report include the name of the organization issuing that report and the report number, if any, and that to a conference presentation gives the title of the conference, the date(s) on which it was held and the place, the name of the organizer(s) of the conference, and so on.
Note that journals or publishers differ in the elements they expect authors to include when they state how to put references in research papers; for example, some journals give only minimal information and exclude the titles of articles and some use the ‘elided’ form of page numbers (737–38 instead of 737–738, for example).
Then there is the question of abbreviated names of journals: some publishers abbreviate journal titles and some don’t (Annals of Applied Biology or Ann. Appl. Biol.). And those who do, often disagree on the correct abbreviation—and on whether the abbreviations should end in dots (whether the word ‘Journal’ should be given as J. or J or Jnl or Jnl.).
Sequence of the elements that make up references in research papers
Publishers and journals also differ in the order or sequence in which they present the elements or components of references in research papers: usually, British and European publishers put the year of publication after the names of authors whereas US publishers move the year closer to the volume number of the journal.
Even within an element, the sequence of references in research papers can have subtle differences. In Harvard system, because the last name of the first author is using for sorting, the name is ‘inverted’, that is the last name is given first, followed by initials (Watson J D instead of J D Watson). However, some journals invert the names of all the authors whereas some invert the name of only the first author. In Vancouver system, the names are seldom inverted because the sequence is not alphabetical.
Punctuation to separate the elements that make up references in research papers
The many exasperating details that go into formatting references include punctuation marks (or their absence). In giving the initials of authors, some journals use dots, some journals use space, some use both, and some use neither (Watson J.D. or Watson J D or Watson J. D. or Watson JD). Some use a comma between the last name and the initials whereas some reserve the comma only to separate one name from the next (Watson, J D and Crick, F H C or Watson J D, Crick F H C). Some use ‘and’ some don’t, even when there are only two authors, and some use ‘&’ instead which makes it even more confusing for those struggling with how to write references in a research paper.
When the place of publication was a required element in the case of books, some publishers used the colon and some used the comma (and also changed the order, as in New York: Harper & Row or Harper & Row, New York).
Some publishers end each reference with a full stop (period) and some don’t.
Typography of references in research papers
As if the variations mentioned above were not enough, when figuring out how to add references in a research paper, you also have to contend with the differences in typography as well: journal titles in italics or in normal type, volume numbers in bold or in normal type, hyphens or en dashes between page numbers (737-738 or 737–738), and so on.
All is not lost, however, if you despair of ever getting the references in a research paper right. For example, some publishers now insist on correct formatting only after a paper has been accepted for publication. Also, ICMJE, the International Committee of Medical Journal Editors, recommends a set of uniform requirements for manuscripts (the requirements include the formatting of citations and references), and hundreds of medical journals (www.icmje.org/journals-following-the-icmje-recommendations/) have agreed that as long as authors adhere to those recommendations on how to mention references for research papers, any changes to the formatting any journal wants to make will be made by the journal in question.
Lastly, several software packages help authors to automate this mundane task of consistent formatting of references in research papers—but that is another article and another day.
The details involved in using citations and references correctly can be overwhelming for some of us. While this article covers the key tips to help you understand how to give references in research papers, be sure to check out article 1 of this two-part series for more on what, when and how to cite in a research paper. One way to check whether these are handled correctly in your manuscript is to use Researcher.Life’s AI powered manuscript optimizer, which can flag any discrepancies, departures from standard style, and mismatches between citations and references in research papers.
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