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Gerstein Science Information Centre

BCH 210H Biochemistry 1: Proteins, Lipids, and Metabolism

Why instructors ask you to cite sources


reasons to cite

Citing Using the Council of Science Editors (CSE) Style

Council of Science Editors (CSE) is one example of a citation style. There are three systems of CSE: (1) name–year system, (2) citation–sequence system, and (3) citation–name system. All three systems require a reference list and in-text references. However, they differ by format. In this Library Guide, we will focus on the name–year system, also known as the author–year or author–date system. Below is a summary of the other two CSE systems, i.e., citation–sequence and citation–name systems. 

Citation–Sequence System: Include superscripts in text to indicate where references have been consulted. List references numerically in the reference list, in the order in which the references have been used. 

Citation–Name System: List references alphabetically in the reference list and assign a number to each reference. When citing in text, consult the reference list for the number associated with the reference, and add in text as a superscript. 

The Name–Year (Author–Year) CSE System

This course requires the use of the name–year CSE system, which can also be referred to as the author–year or author–date system. Please see below for examples of in-text citations and reference list entries that follow the formatting required by the name–year system. 

In-Text Citations 

In-text citations include the author’s last name and the year of publication in parentheses (e.g., Williamson 1996). Do not include a comma between the author(s) and publication year. If there are three or more authors, use “et al.” (stands for et alia, a Latin expression for “and others”), followed by the year. Use abbreviations in instances where the author is an organization (e.g., university, non-profit organization, corporation, government body). When citing an encyclopedia article, or a chapter in an edited book, use the author of the article or chapter, not the editor of the book itself. Please see below for examples of in-text citations: 

Source with one author: (Nishizuka 1988)
Source with two authors: (Carmeliet and Jain 2011)
Source with three or more authors: (Perou et al. 2000)
Multiple sources in one sentence: 
(Nishizuka 1988; Perou et al. 2000; Carmeliet and Jain 2011)
Multiple sources with the same author(s) with the same year: (Hawkey 2008a; Hawkey 2008b)
Organization as an author: 
(WHO 2013)


Reference List 

Use the term “References” to title your list of sources. Do not use any hanging indents. List references in alphabetical order, by authors’ last names. Only include information for the first ten authors. Note that there are no periods between initials and that species names are always underlined or italicized—e.g., Lau and Galloway (2004) tested the preferences of pollinators visiting Campanula americana

Journal Article

A journal article uses the following format. Apply sentence case, capitalizing the first word, proper nouns, and acronyms for journal article titles. To preserve space, the name–year CSE system asks that there be no spaces between the volume, number, and page numbers and that the abbreviated journal title be used. A list of abbreviated journal titles can be found on ISI Web of Science or on the Chemical Abstracts Service.

Author(s). Year. Title of article. Journal. Volume(Number):Page numbers.  

Nishizuka Y. 1988. The molecular heterogeneity of protein kinase C and its implications for cellular regulation. Nature. 334(6184):661–665.

Chapter in Edited Book

Apply sentence case, capitalizing the first word, proper nouns, and acronyms for book chapter titles. Use the following for formatting: 

Author(s). Year. Chapter title. In: Editor(s). Book title. Place of publication: Publisher. Page numbers. 

Pollard TD, Earnshaw WC, Lippincott-Schwartz J, Johnson GT, editors. 2017. Chapter 1 - Introduction to Cells. In: Cell Biology (Third Edition). Amsterdam: Elsevier. p. 3–14. 


Use the following format for books. Note that the extent is the total number of pages. 

Author(s). Year. Book title. Edition (if applicable). Place of publication: Publisher Extent.

Elliott D, Ladomery M. 2016. Molecular Biology of RNA. Oxford: Oxford University Press 426 p. 


When referencing a website, be sure to include the medium designator (i.e., Internet). Please see below for how to format a website reference. 

Website title [Medium designator]. Year. Place of publication: Publisher; [date updated; date cited]. Available from: URL

Mathematics [Internet]. 2022. Toronto: University of Toronto; [updated 2022 Mar 1; cited 2022 Apr 29]. Available from:

Internet Resource

Internet resources similar to website references require a medium designator. Please see below for a template and example. 

Author(s). Year. Title of page [Medium designator]. Place of publication: Publisher; [date cited]. Available from: URL

Gerstein Science Information Centre. 2022. BCH 210H Biochemistry 1: Proteins, Lipids, and Metabolism [Internet]. Toronto: University of Toronto; [cited 2022 Apr 29]. Available from:

More Resources on the Name-Year CSE System