Citing References in Text

When to cite

A source must be cited whenever your paper uses research results, language, or ideas that originated with someone other than yourself. You should even cite results and ideas that are entirely your own, if they have been previously published.

Even though review writing depends entirely (or almost entirely) on the words and ideas of others, direct quotation - the exact language of the original source - is seldom used. When words are taken directly from a source, quotation-marks must be used. Quotation-marks must be used even if only a single phrase is quoted, if the phrase is distinctive. For quotations several lines in length, indented single-spaced type is used instead of quotation-marks, but quotations of that length are extremely rare in scientific writing.

If you base several consecutive sentences on the same source, cite the source in the first of these sentences. The reader assumes that what follows comes from the same source until another source is cited, or until you begin a new paragraph, in which case you should cite the source again. Good review writing integrates ideas from different sources. If you find yourself writing several consecutive sentences or an entire paragraph based on only one source, consider ways to incorporate ideas from other sources.

Name-and-Year System

Different journals handle citation form differently. One standard form is the name-and-year form of citation, also known as the Harvard system. This is the expected form for San Francisco State University theses in Biology, and is the required form for the project for Biology 700. The guidelines that follow are based on Council of Biology Editors Style Manual Committee (1994).

References are cited by author(s) name(s) and year. If there is only one author, the form is:   Author (year) if the author name is used in a sentence in your paper;   if not, the form is (Author year).     If there are two authors, the form is:   First and Second (year);   or (First and Second year).     If there are three or more authors, use:   First and others (year);   or (First and others year).     In good review writing the two forms, 'name (year)' and '(name year)', are both used. The choice depends on whether or not you use the author(s) name(s) in the sentence. Interspersing references of the 'name (year)' form with those of the '(name year)' form tends to improve readability.     When you use the author(s) name(s) in the sentence, the date immediately follows the name(s).   Drewes (1996) reports this phenomenon.*   Jolly and others (1998) report this phenomenon.     Commonly, in the '(name year)' form the parenthetical reference is at the end of the sentence (just before the period that ends the sentence). You may want to locate the reference elsewhere, though, especially if the sentence includes more than one citation.   This phenomenon has been observed in rhinoceroses (Berger and Cunningham 1992), baboons (Jolly and others 1998), and treefrogs (Drewes 1996).     If you wish to offer more than one attribution (citation) at the same point in the text, the correct form is:   (Author year, Author year, Author year).     The citations within parentheses should be in date order, earliest first, unless there is clear reason to arrange them otherwise.   This phenomenon has been observed in diverse taxa (Berger and Cunningham 1992, Drewes 1996, Jolly and others 1998).     When you are tempted to pile up more than three citations at the same point in the text, consider other ways of accomplishing the desired result.   A number of researchers observed this phenomenon (for example, Berger and Cunningham 1992, Drewes 1996).     Punctuation   Parenthetical citations are within the sentence, so the period that ends the sentence comes after the closing parenthesis. The citation for a direct quotation follows the quotation, outside the quotation-marks but before the period that ends the sentence, unless you have used the author(s) name(s) before the quotation, in which case the date directly follows the name(s) as usual.     There is no comma between author name and date, or between the first author and 'and others'. If several citations occur within the same parentheses, commas are used to separate them.     Reference List     The reference list (usually entitled 'References Cited', or 'Literature Cited', or just 'References') at the end of the paper includes every reference cited in the text, and is alphabetized by (first) authors. Within each citation in the reference list, all authors are named in exactly the order in which they are named in the heading of the cited paper.     * Note: all examples herein in parentheses are fictional. Were they real, the complete citation for each should be included in the list of references cited.

Reference Cited

Council of Biology Editors Style Manual Committee. 1994. Scientific style and format: the

CBE manual for authors, editors, and publishers. 6th ed. Cambridge:   Cambridge University Press. 825 p.     Return to Biology 700 homepage.