TIPSHEET: APA DOCUMENTATION IN THE SCIENCES
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Guide to the American Psychological Association’s citation style focusing on requirements in the sciences
WHY SHOULD I REFERENCE?
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Identify and acknowledge you sources of
information and research
Strengthen your academic work: References can
strengthen your academic work by demonstrating that
the statements you are making are based on evidence.
Allow readers to find out more: Finally, references
allow readers to follow up on points of interest or
obtain more detailed information by finding the same
resources you used.
Avoid plagiarism: If you do not document
information sources that are not your own, you are
representing someone else’s work as yours. This is
plagiarism, whether you have done it intentionally or
not.
WHAT SHOULD I REFERENCE?


Reference all paraphrased, summarized, or quoted
material in your paper. Note: In the sciences
quotations are rarely used.
You don’t need to cite facts that are common
knowledge, but err on the side of caution. Ask your
instructor if you’re uncertain.
WHAT STYLE SHOULD I USE?
Ask your instructor which documentation style is
required. This sheet outlines APA style, from the
Publication Manual of the American Psychological
Association (6th ed., available from the MRU Library).
HOW DO I REFERENCE?
There are two steps involved in referencing:
1) In-text citation: Identifies within the written text of
your assignment the ideas and information you have
selected from other sources.
2) Reference list: Provides the full bibliographic citation
(title, author, etc.) for each source of information used
in your paper.
ADDITIONAL RESOURCES
Get more APA examples and explanations by clicking on
“Cite Sources” on the MRU Library homepage
(mtroyal.ca/library).
Updated August 2016 by Student Learning Services and MRU Library.
1.
IN-TEXT CITATIONS
In-text citations include
 author’s last name
 publication year
 page number indicating where you found the
information in the original text.
You can include these citations in various ways:
• At the end of the sentence in parentheses
One study tested this hypothesis (Smith, 1970, p.
787).
• As part of the sentence, using the parentheses to include
whatever reference information is not in the sentence
Smith (1970) tested this hypothesis (p. 787).
IN-TEXT CITATION EXAMPLES
These formats apply to both electronic and print sources.
ONE OR TWO AUTHORS
… (Elias & Williams, 1981, pp. 56-57).
Elias and Williams (1981, pp. 56-57) describe…
THREE TO FIVE AUTHORS
List all authors the first time you cite the reference
…(Brasch, Mendling, & Allen, 2015, p. 85).
In subsequent citations use et al. to replace all but the first author
Brasch et al. (2011) demonstrated…(p.89).
SIX OR MORE AUTHORS
Use et al. from the first instance of the reference
… (Lui et al., 2015, p. 76).
ANONYMOUS AUTHOR / NO AUTHOR
Do not use “Anonymous.” Instead, use a shortened title of
the article (in quotation marks) or book (in italics) in place
of the author’s name.
… (“Pathogenesis and Management,” 2010, p. 5).
ORGANIZATIONS, INSTITUTIONS, ETC. AS GROUP
AUTHORS
A group may serve as an author if no personal author is
listed.
… (World Health Organization, 2016, p. 5).
NO DATE AVAILABLE
Use n.d. to indicate “no date” available in place of the date.
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If the document has headings, use the heading of the section,
and then give the number of the paragraph under it that
contains the information you are using.
. . . (Meckler, 2011, Methods, para. 2).
If there are no headings, count the paragraphs from the
beginning of the document.
. . . (Jacobs, 2014, para. 4).
PERSONAL COMMUNICATIONS
Email, personal or telephone interviews, conversations, or
lectures are not widely retrievable (i.e., unpublished). Cite
them in the text of your paper only. Provide the initials
and last name of the communicator and the date of the
communication.
… (T. Vela, personal communication, April 25, 2012).
… (Smith, n.d., p. 54).
MULTIPLE SOURCES, SAME AUTHOR
COURSE AND LECTURE MATERIALS
Order them chronologically, earliest to latest, separated
with a semi-colon.
Instructor-created course handouts / items posted to
Blackboard: Use the instructor as the author and the date
on the handout as the year of publication.
…(Jones, 1965, p. 222; 1973, p. 399; 1988, p. 45).
If there are several in the same year, add a designator (a, b,
c, etc.) to the year in the citation and the reference list.
… (Jones 1998a, p. 151; 1998b, p. 765).
MULTIPLE SOURCES, DIFFERENT AUTHORS
List source citations alphabetically; separate them with a
semi-colon.
… (Alberts et al., 2001, p. 171; Klevezal & Thompson,
1980, p. 333; Sergeant, 1973, p. 12).
CITING A SOURCE CITED IN ANOTHER SOURCE (AKA
secondary source)
Include only the source you have seen (e.g., Brown) in your
reference list.
. . .King in 1911 found that…(as cited in Brown, 2003,
p. 181).
Note: When the source you’re citing is within another
source, obtaining the original paper (e.g., King) is the best
option whenever possible.
NO PAGE NUMBERS ARE AVAILABLE
If you have a source such as a website, with no page
numbers use the paragraph number instead.
Updated August 2016 by Student Learning Services and MRU Library.
… (Nickle, 2016, para. 1).
Lab manuals: Treat these as books (print) or as web
documents (if they are on Blackboard), using the instructor
as author (unless another author is indicated, i.e., the
department).
… (Department of Chemistry, 2016, p. 2).
Lecture notes that you took in class: See previous section
for information on citing personal communications.
Article from a course pack: See B2 on page 7 of the MRU
APA handout for an example.
2.
REFERENCE LIST
The reference list:
 comes at the end of your paper
 provides the full bibliographic information for your
sources
 only includes the references cited in your paper
Your references must:
 start on a new page with the centered title References
 be double spaced with a ½ inch hanging indent, and
 be listed in alphabetical order by last name of first
author (in the order listed on the article) or by title
(when there is no author).
REFERENCE LIST EXAMPLES
For more examples see the full MRU APA guide or refer to
the APA publication manual.
JOURNAL ARTICLE WITH A DOI (print or electronic)
A doi (digital object identifier) is a unique reference that identifies
the article; include doi information if it is provided.
Author A. A., & Author, B. B. (Year). Article title. Journal
title, volume number(issue number), inclusive
pages. http://dx.doi.org/doi
Armstrong, C. L., Duffin, C. A., McFarland, R., & Vogel, M. W.
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If from journal homepage, include journal homepage URL in place
of database name (i.e., http://onlinelibrary.wiley.com/)
JOURNAL ARTICLE IN PRESS, RETRIEVED FROM THE
WEB
Articles in press
 have only been informally published (for example, in a
preprint archive or on the author’s website)
 are not usually indexed in a journal website
Author, A. A., & Author, B. B. (In press). Article title.
Journal Title. Retrieved from URL
Palamara, G. M., Delius, G. W., Smith, M. J., & Petchey, O. L.
(2011). Mechanisms of compartmental purkinje cell
(In press). Predation effects on mean time to
death and survival in the lurcher mutant mouse.
extinction under demographic stochasticity. Journal of
Cerebellum, 10(3), 504-514.
Theoretical Biology. Retrieved from
http://dx.doi.org/10.1007/s12311-010-0231-4
http://arxiv.org/pdf/1205.6989
JOURNAL ARTICLE WITH MORE THAN SEVEN
AUTHORS WITHOUT A DOI (print or electronic)
Update your references as close as possible to the day you submit
your work in case of new information.
Author A. A., Author, B. B., Author, C., Author, D. D.,
JOURNAL ARTICLE, ADVANCED ONLINE
PUBLICATION
List the first 6 authors, use … and then list the final author.
Author, E., Author, F. F., . . . Author, X. X. (Year).
Article title. Journal title, volume number(issue
number), inclusive pages.
Percival, P. W., McCollum, B. M., Brodovitch, J.-C., Driess,
M., Mitra, A., Mozafari, M.,. . .Yao, S. (2012). Dual
reactivity of a stable zwitterionic N-heterocyclic
Advanced online publications
 are offered online, usually from the journal homepage
 are normally peer reviewed but may not have been copy
edited or formatted
 may have no volume, issue, or page numbers yet
Author, A. A., Author, B. B., & Author, C. C. (Year). Article
title. Journal Title. Advance online publication.
http://dx.doi.org/doi
silylene and its carbine complex probed with
muonium. Organometallics, 31(7), 2709-2714.
Benediktsson, A. M., Marrs, G. S., Tu, J. C., Worley, P. F.,
Rothstein, J. D., Bergles, D. E., & Dailey, M.E. (2012).
ABSTRACT FROM A JOURNAL ARTICLE
Neuronal activity regulates glutamate transporter
Note: It is preferable to cite from the full text of an article, if
possible.
dynamics in developing astrocytes. GLIA. Advance
Author A. A., & Author, B. B. (Year). Article title. Journal
online publication.
http://dx.doi.org/10.1002/glia.21249
title, volume number(issue number), inclusive
pages. Abstract retrieved from database name.
Ackroyd, N. C., & Katzenellenbogen, J. A. (2010). Pyridylcyclopentadiene Re(CO)2+ complexes as a compact
core system for SPECT ligand development.
Organometallics, 29(16), 3669-3671. Abstract
retrieved from Scopus database.
Updated August 2016 by Student Learning Services and MRU Library.
If no doi, include URL for the journal homepage. Update reference
just before submitting, in case of new information.
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BOOK
Author, A. A., & Author, B. B. (Year). Title of book
(edition). Place of publication: Publisher name.
Marieb, E. N., & Hoehn, K. (2012). Human anatomy &
physiology
(9th
ed.). San Francisco, CA: Pearson
Benjamin Cummings.
CHAPTER OF AN EDITED BOOK
Author(s) of the chapter. (Year). Title of chapter. In
Editor(s), Title of the book (pp. page numbers).
Place of publication: Publisher name.
Day, T. (2010). Human adaptation to high altitude hypoxia:
DOCUMENT ON A WEBSITE LINKED TO A COURSE
BLACKBOARD SITE
Author. (Date). Title of document. Retrieved from Mount
Royal University course name Blackboard
website: URL
Department of Chemistry. (2013, Winter). Experiment 2:
Atomic spectroscopy. Retrieved from Mount Royal
University CHEM 1201 Blackboard website:
http://courseware.mymrc.ca/@98055A6CB5BC4E990
D2994115D8/Lab_Manual_Intro.pdf
Italicize the titles of documents and reports found on websites.
WEBSITE, ORGANIZATION/GROUP AS AUTHOR
Getting high. In S. L. Gillies & S. A. Hewitt (Eds.),
A group may serve as an author if no personal author is listed.
Biology on the cutting edge: Concepts, issues and
Group or organization. (Year). Title of webpage. Retrieved
Canadian research around the globe (pp.117-122).
Toronto, Canada: Pearson Education.
ELECTRONIC BOOK RETRIEVED FROM A LIBRARY
DATABASE
Author, A. A., Author, B B. , & Author, C. C. (Year). Title of
work. Retrieved from name of database.
Luisi P. L. (2006). The emergence of life: From chemical
origins to synthetic biology. Retrieved from ebrary
database.
access date, from URL
Canadian Centre for Occupational Health and Safety. (2005).
Hydrogen sulfide. Retrieved September 30, 2012,
from http://ccinfoweb2.ccohs.ca
/cheminfo/Action.lasso?-database=cheminfo
ANONYMOUS AUTHOR / NO AUTHOR, DATE
UNKNOWN
Omit authorship from reference, and begin with title. Use n.d. to
indicate that there is no date.
Title. (n.d.). Retrieved date, from URL
LAB MANUAL
Organic nomenclature - alkanes. (n.d.). Retrieved September
Print manual
10, 2012, from http://www.sciencegeek.net
Author. (Date). Title. Place of publication: Publisher.
/APchemistry/organic/ochem.shtml
Department of Chemistry. (2012, Fall). CHEM 0130 Basic
Chemistry II laboratory manual. Calgary, Canada:
Mount Royal University.
GOVERNMENT REPORT ON A WEBSITE, WITH
IDENTIFIED AUTHOR
Author. (Year). Title. Retrieved from URL
Manual available on Blackboard
[See next section on citing a document from Blackboard]
Sanner, M. (2010). A primer on scientific risk assessment at
Health Canada. Retrieved from http://www.hc
-sc.gc.ca/sr-sr/pubs/about-apropos/2010-scientifris/index-eng.php
Italicize the titles of documents and reports found on websites.
Updated August 2016 by Student Learning Services and MRU Library.