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BIOL 125: Ecology, Evolution, and Diversity: CSE Style (Biology)

Citing Sources

As a scholar, you need to cite the sources that you use in your research. Your discipline determines the citation style you use. Biology, for example, commonly uses both Council of Science Editors (CSE) and the American Psychology Association (APA) citation styles. Citations are important because they:

  • legitimize our arguments
  • provide a form of backing for what we are saying
  • provide context for the larger conversation around a topic
  • show the work of others
  • provide bread crumbs for others to trace our ideas

In-Text Citations

Basic form for in-text citations: Parentheses are placed around the author's surname and year of publication, for example (Smith 2025). Remember to paraphrase content with your own words; quotes are rarely used in scientific publications.

 
Single author
The NIH has called for a change in smallpox vaccination policy (Kennedy 2025) that...
Two authors
When a work has 2 authors, give both names and separate them by "and" plus the year in between parentheses. If the authors have the same surname, include their first initials.
In a recent study (Williams and Jones 2013) found...
In a recent study (Williams T and Williams B 2013) found...
Three or more authors
When a work has more than two authors, give only the first author's name followed by "et al." and the publication year.
... but later studies (Ito et al. 2014) established that...
ChatGTP & AI
AI generated content can be cited in-text with the following format of other unpublished materials: (Author, Format, Date [DMY]).
... an search on ChatGTP (OpenAI, Chat GPT, 10 May 2025) suggests that...
Corporations or organizations as authors
If the author is an organization, committee, or corporation, a shortened form may be created for the in-text reference to avoid interrupting the text with a long string of words. Use the initial letters of each part of the name or a readily recognizable abbreviation.  Include your abbreviation in square brachets for your reference list.
The landmark report on legalized abortion ([IOM] 1975) was...
No author
If the author cannot be determined, do not use "anonymous."  Instead, substitute it with an organization name if one is available.  And if there is no organization, use the first word or few words of the title, followed by ellipsis. Only use enough words of the title to distinguish it from other titles. 
Drug dosage recommendations for elderly patients (Handbook... 2000) depart from...
No date
Occasionally it is not possible to determine any date associated with a publication.  If the document was found online, use the date you viewed it instead.  Alternatively for print publications, place the words "date unknown" within square brackets. 
Only one study (Hamilton 2014) relating the adverse effects of hormone...
Only one study (Hamilton [date unknown]) relating the adverse effects of...

Reference List

The reference list is located at the end of a document under the heading "Reference," "Cited References," Literature Cited," or "Bibliography." It alphabetically lists and matches the sources cited within the text, including tables and figures.

 
Articles (1 to 10 Authors)
Pierce JP, Messer K, White MM, Cowling DW, Thomas DP. 2011. Prevalence of heavy smoking in California and the United States, 1965-2007. JAMA 305(11): 1106-1112.
Article (11 or More Authors)
Edmunds W, Pebody R, Aggerback H, Baron S, Berbers G, Conyn-Van SM, Hallander H, Olander R, Maple P, De Melker H, et al. 2000. The sero-epidemiology of diptheria in Western Europe. Epidemiol Infect 125(1):113-25.
Article (From Internet)
Halford NG, Curtis TY, Muttucumaru N, Postles J, Mottram DS. 2011. Sugars in crop plants. Ann Appl Biol [Internet] [cited 2014 Feb 2]; 158(1):1-25. Available from: http://www.blackwellpublishing.com/journal.asp?ref=0003-4746 doi:10.1111/j.1744-7348.2010.00443.x
 
Blog Post
Salopek P. 2014 Apr 17. The river door [blog post]. Out of Eden walk: dispatches from the field from Paul Salopek. [assessed 2014 May 19]. http://outofedenwalk.nationalgeographic.com.
Book
McCormac JS, Kennedy G. 2004. Birds of Ohio. Auburn (WA): Lone Pine.
Book Chapters
Cantrill J. 1996. Gold, Yellowstone, and the search for a rhetorical identity. In Herndl C, Brown S, editors. Green culture: environmental rhetoric in contemporary America. Madison (WI): University of Wisconsin Press. p. 166-194.
Book with Editors
Herndl CG, Brown SC, editors. 1996. Green culture: environmental rhetoric in contemporary America. Madison (WI): University of Wisconsin Press.
Book with no Author
CRC handbook of chemistry and physics. c2008. Cleveland (OH): CRC Press.
 
CD, DVD, or Blu-ray Disc
NOVA: secrets beneath the ice [DVD]. Seifferlein B, editor; Hochman G, producer. Boston (MA): WGBH Educational Foundation; 2010. 1 DVD: 52 min.
ChatGTP & AI
Although there is no specific guidance offered by CSE, AI content is considered personal communication and/or non-recoverable data. Therefore it should not be included as a reference in your reference list according to CSE style. It should be included in the text of your paper. (see in-text example)
 
CD, DVD, or Blu-ray Disc
NOVA: secrets beneath the ice [DVD]. Seifferlein B, editor; Hochman G, producer. Boston (MA): WGBH Educational Foundation; 2010. 1 DVD: 52 min.
E-Book
Williams R, Johnson P. 2008. Genetic policing: the use of DNA in chemical investigations [Internet]. Portland (OR): Willan Publishing; [cited 2014 Sept 30]. Available from NetLibrary: http://www.netlibrary.com/
Conference Proceeding
Clarke A, Crame JA. 2003. Importance of historical processes in global patterns of diversity. In: Blackburn TM, Gaston KJ, editors. Macroecology: concepts and consequences. Proceedings of the 43rd annual symposium of the British Ecological Society; 2002 Apr 17-19; Birmingham. Malden (MA): Blackwell.
Encyclopedia Entry (Print)
Robertson MP. 2009. Origins of life: emergence of the RNA world. In: Wiley encyclopedia of chemical biology. Vol. 3. Hoboken (NJ): John Wiley & Sons. p. 517-28.
Image
Red blood clot. Encyclopedia Britannica Online [Internet] [cited 2014 Sept 19]. Available from http://www.britannica.com/eb/art-100538.
Images from Print Resource
Bronze MS, Greenfield RA. 2005. Biodefense: principles and pathogens. Norfolk: England.
Newspaper Article
Azar B, Martin S. 1999 Oct. APA's Council of Representatives endorses new standards for testing, high school psychology [Internet]. APA Monitor. [cited 2014 Sept 19]. Available from http://www.apa.org/monitor/tools.html.
 
Online Video
Life: creatures of the deep: nemertean worms and sea starts [video]. 2010 Ma 21, 2:55 min. Gunton M, executive producers; Holmes M, series producers. [accessed 2011 Feb 4]. http://dsc.discovery.com/videos/life-the-series-videos/?bcid=73073289001. 
 
Podcast
Mirsky, S, host; Conrad N, interviewee. 2011 Feb 17, 19:26 min. The spirit of innovation: from high school to the moon [podcast]. Sci Am. [accessed 2021 Oct 1]. http://www.scientificamerican.com/podcast/episode.cfm?id=from-high-school-innovation-to-the-11-02-17.
Technical Reports (Govern. Publications)
Ford PL, Fagerlund RA, Duszynski DW, Polechla PJ. 2004. Fleas and lice of mammals in New Mexico. Fort Collins (CO): USDA Forest Service Rocky Mountain Research Station. General Technical Report NR RMRS-GTR-123.
Theses/Dissertations
Dettmers JM. 1995. Assessing the trophic cascade in reservoirs: the role of an introduced predator [dissertation]. Columbus (OH): Ohio State University.
Website (Government websites)
Bush G. 1989 Apr 12. Principles of ethical conduct for government officers and employees [Internet]. Executive Order 12674. Part 1 [cited 2014 Feb 20]. Available from http://www.usoge.gov/exorders/eo12674.html.
Website (No author)
Substitute the author with one of these alternatives and in this order:
Organization name, Document title, or Page title.
[USDA] United States Department of Agriculture [Internet]. 2004. USDA announces first steps to update biotechnology regulations [cited 2014 Sept 19]. Available from http://www.usda.gov/Newsroom/0033.04.html.
Website (No publication date)
Substitute the publication date with the access date -- the date which you viewed the website.
APHIS. APHIS Hot issues [Internet] [cited 2014 Sept 19]. Available from http://www.aphis.usda.gov/lpa/issues/wnv/wnv.html.
Website (Personal site)
APSnet: plant pathology online [Internet]. c1994-2005. St. Paul (MN):American Phytopathological Association; [cited 2014 Sept 19]. Available from http://www.apsnet.org.
Website (Professional organizations)
Medtext, Inc [Internet]. 2008. Hypertension, dialysis and clinical nephrology - kidney [cited 2014 Sept 19]. Available from http://www.medtext.com/hdcn.htm.

About the CSE

The Scientific Style and Format: The CSE Manual is generally used for the Sciences and has been used by the WU biology department. The examples have been adapted from this manual and demonstrate how to document common source materials.

 

Check our print copy for more examples or ask a librarian for help. The print copy is located on a wooden stand next to the reference collection on the first floor of the Hatfield Library. Also, we have other citation guides such as APA. 

 

About Zotero

Zotero is a free citation app that collects, manages, cites, and shares your research sources. The browser extension saves the citation info about articles, books, and more, then connects with the desktop Zotero to create citations and work with Google Docs (you need both desktop and browser extension). 

 

More info at https://libguides.willamette.edu/zotero

 

For Zotero help, contact:
Bill Kelm, bkelm@willamette.edu or
John Repplinger, jrepplin@willamette.edu

Willamette University

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