Reference formatting, in-text citations

Back in February I posted about selecting and formatting references in a manuscript. Since then I have noticed some other general styling concerns that persist regardless of a particular journal’s instructions.

  • Always cite a source at the first mention of a source, not at the end of several sentences reporting information from that source.
  • If you refer to a source by author names, e.g., “Smith et al described …” the reference numeral should still be placed at the end of the sentence. But, if more than one author or set of authors are named in the same sentence, place reference numerals after each set of names. “Smith et al1 and Higgins2 reported …” Or “Smith et al1 and others2-4 have reported …”
  • When citing references using superscript numerals, remember that the numerals always go outside the period at the end of a sentence or a comma in the middle of a sentence. Superscript numerals generally go inside other punctuation, such as colons and semi-colons.

Outside: Prineas et al first documented the spur on the hind feet of the male duck-billed platypus.1
Inside: Ferber built on this observation with multiple other discoveries2: its aquatic abilities, its lizard-like walk, and its venomous secretions.

  • If instructions call for reference numerals to be placed in parentheses or square brackets, these go inside the period at the end of a sentence as well as all other punctuation. “Smith et al first reported this mechanism in 1988 (1).” The same rule applies when citing by author name(s) and year.

Where things can get a little tricky is when using EndNote. EndNote will format your reference numbers for you in your paper, but make sure to find the right journal or EndNote style so that reference numbers are inserted in the correct format for your target journal.

And, of course, as I always mention when writing any manuscript, follow the instructions given. If instructions aren’t clear or you’re not sure how to cite a source, skim through several recently published articles to find examples in the journal to which you want to submit. 

Or ask your friendly local editor!

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