Citation Styles

A citation or reference is the information given in a bibliography or a database about a particular title, which often includes:

• article title or chapter title
• periodical title or book title
• author(s) or editor(s)
• place of publication
• date of publication
• publisher name
• volume/issue (articles) or edition (books)
• page range
• medium of publication
• electronic access (URL or DOI)
• date accessed

Citations give credit to those whose ideas have contributed to your research and give your readers enough information to locate the sources you used. There are many ways to format citations. The style you choose depends on your field and the requirements set by your professor or publisher.

The Council of Science Editors uses three systems to format in-text citations and the order of end-of-text citations in your reference list. These are:

• name-year
• citation-name
• citation-sequence

This guide focuses on the name-year style used in the biological and earth sciences. In addition to following the rules below, ask your professor if they have any special requirements for formatting your references.

• References in the reference list are ordered alphabetically by last name of the author
• Two or more references by the same author are ordered by date
• Only the first word of a book, chapter, or article title is capitalized
• Journal titles are abbreviated according to ISO 4 (see the List of Title Word Abbreviations).
• Every word of a journal or newspaper title is capitalized
• An article's volume, issue, and page range are not separated by spaces.

For complete information about formatting requirements for any of the styles, see the CSE manual.

All sources that are directly quoted or paraphrased must be cited within your text, as well as in your reference list.

The author's last name and the year of the publication should be included in parentheses as close as possible to the information referred to in the text.

• The raccoon dog's average movement rate and home range were found to be larger in autumn (Saeki et al. 2007)...

If you mention the author's last name in the text, you do not need to include it in the citation.

• Balmant et al. identified many potential protein redox switches (2015)...

For more in-depth information about citing articles with multiple authors, multiple articles by the same author, and more, visit the Writer's Handbook online or refer to the CSE manual in the library's reference collection.