SPAN 322: Cite Sources

This page includes guidelines for two common citation styles, APA and MLA. If you are using another style and have questions, feel free to email the Science Librarian, Tessa Withorn (tessa.withorn@louisville.edu). 

Ask your professor which style they would like you to use for your assignment. If you get to choose, I highly recommend APA! 

• APA
  • In-text citations
  • References
• MLA
  • In-text citations
  • Works Cited

This guide is a quick introduction to the American Psychological Association (APA) Style for in-text citations and references. Be sure to consult the Publication Manual of the APA or the APA Style website for detailed standards and procedures.

You can also find sample papers with annotations and a Word template on APA Style's website. 

When you reference another source, use an in-text citation in the body of your paper.

Paraphrasing or summarizing the main findings or takeaways from a research article is the preferred method of citing sources in an APA paper. Always include the last name of the author(s) and the year of the article, so your reader can find the full citation in the reference list. These citations can be written narratively or in parentheses at the end of the sentence. Any sentence punctuation goes after the closing parenthesis. See more examples of formatting parenthetical versus narrative in-text citations from APA Style's official website.

Narrative In-text Citation

According to Shavers (2007), limitations of studying socioeconomic status in research on health disparities include difficulties in collecting data on socioeconomic status and the complications of classifying women, children, and employment status.

Parenthetical In-text Citation

Limitations of studying socioeconomic status in research on health disparities include difficulties in collecting data on socioeconomic status and the complications of classifying women, children, and employment status (Shavers, 2007).

If you're quoting the exact words of someone else, include an in-text citation with the page number(s). See more examples of quotations from APA Style's website. 

In-text citations differ depending on the number of authors listed for a work, and if there is a group author.

1 Author

You only need the author's last name comma year in parentheses.

(Abrams, 2018)

2 Authors

Connect both authors' last names with & (ampersand) comma and the year.

(Wegener & Petty, 1994)

3 or More Authors

If there are 3 or more authors use et al., which is Latin for "and others," comma and the year.

(Harris et al., 2018)

Group Author

First time with an abbreviation:

(Centers for Disease Control and Prevention [CDC], 2019)

Then all subsequent citations:

(CDC, 2019)

Include the complete citation at the end of your paper in a references section. References are organized by the author's last name in alphabetical (A-Z) order. Use an hanging indent to separate each list item.

Use the following directions and examples to format these common types of sources. You can find a comprehensive list of reference examples on APA's website. 

Journal Article

1. Author(s). List each author's last name and initials as Author, A. A., Author, B. B., & Author, C. C. Use an ampersand (&) before the final author's name. Read more from the APA Style website if there are 21 or more authors.

2. (Year).

3. Title of the article. For works that are part of a greater whole (e.g. articles, chapter), use sentence case. Only the first word of the title and subtitle and proper nouns are capitalized.

4. Title of the Journal, Italicize and capitalize each word in the journal. You can use headline-style capitalization. 

5. Volume Italicize the journal volume number. If there is no issue, include a comma before the page range.

6. (Issue), If there is a issue number in addition to a volume number, include it in parentheses.

7. Page range. If there is no page range within the journal volume/issue, this can be excluded.

8. DOI (Digital Object Identifier) This is a direct link to the article on the publisher's website. Read more about DOIs from APA Style's website.

Toledo, D., Sanderson, M., Spaeth, K., Hendrickson, J., & Printz, J. (2014). Extent of Kentucky bluegrass and its effect on native plant species diversity and ecosystem services in the Northern Great Plains of the United States. Invasive Plant Science and Management, 7(4), 543-552. https://doi.org/10.1614/IPSM-D-14-00029.1

Book

1. Author(s). List each author's last name and initials as Author, A. A., Author, B. B., & Author, C. C. Use an ampersand (&) before the final author's name.

2. (Year).

3. Title of the book. Note: For works that stand alone (e.g. books, reports), italicize the title. Only capitalize the first word of the title and subtitle and any proper nouns.

4. (Edition). If there is an edition or volume, include it in parentheses and use abbreviations of ed. or vol.

5. Publisher. You do not need to include the publisher location or databases where you retrieved it.

Richtel, M. (2019). An elegant defense: The extraordinary new science of the immune system (1st ed.). William Morrow.

Book Chapter with Editors

1. Author(s). List each chapter author's last name and initials as Author, A. A., Author, B. B., & Author, C. C. Use an ampersand (&) before the final author's name.

2. (Year).

3. Title of the chapter. For works that are part of a greater whole (e.g. articles, chapter), use sentence case. Only the first word of the title and subtitle and proper nouns are capitalized.

4. In Editor(s), List each editor's initials and last name as A. A. Editor, B. B. Editor, & C. C. Editors, include (Ed.) or (Eds.) in parentheses, and end with a comma.

5. Title of the book For works that stand alone (e.g. books, reports), italicize the title. Only capitalize the first word of the title and subtitle and any proper nouns.

6. (pp. xx-xx).

7. Publisher. You do not need to include the publisher location or databases where you retrieved it.

Khan, J. S., Provencher, J. F., Forbes, M. R., Mallory, M. L., Lebarbenchon, C., & McCoy, K. D. (2019). Parasites of seabirds: A survey of effects and ecological implications. In C. Sheppard (Ed.), Advances in marine biology (pp. 1-50). Academic Press. 

Website

1. Author(s). List each author's last name and initials as Author, A. A., Author, B. B., & Author, C. C. If there is no author, spell out the name of the organization or site.

2. (Year, Month Date). Read more about date formats from the APA Style website. Provide as specific a date as is available. Use the date last updated, but not the date last reviewed or copyright date. If there is no date, use (n.d.).

3. Title of page or section. Italicize the title of the page and use sentence case.

4. Source. Usually the official name of the website. If the source would be the same as the author, you can omit the source to avoid repetition.

5. URL

Healing Mushrooms. (n.d.). A comprehensive list of common wild mushrooms in Kentucky. https://healing-mushrooms.net/kentucky

This guide is a quick introduction to the Modern Languages Association (MLA) Style for references and citations. Be sure to consult the MLA Handbook or the MLA Style Center website for detailed standards and procedures, how to format an MLA paper, and sample student papers. 

When you reference another source, use an in-text citation in the body of your paper. Include the author(s) last name and the page number. If there is no page number, you can exclude it. 

For more guidelines and examples, check out the MLA Style Center In-Text Citations Overview.

These citations can be written narratively or in parentheses at the end of the sentence. 

Narrative In-text Citation

According to Shavers, limitations of studying socioeconomic status in research on health disparities include difficulties in collecting data on socioeconomic status and the complications of classifying women, children, and employment status (1021).

Parenthetical In-text Citation

Limitations of studying socioeconomic status in research on health disparities include difficulties in collecting data on socioeconomic status and the complications of classifying women, children, and employment status (Shavers 1021).

In-text citations differ depending on the number of authors listed for a work, and if there is a group author.

1 Author

You only need the author's last name and the page number.

(Burke 3)

2 Authors

Connect both authors' last names with and, and include the page number.

(Best and Marcus 9)

3 or More Authors

Use the first author's last name and et al., and include the page number.

(Franck et al. 327)

No Author

Use the group author or a shortened title of the work.

(Centers for Disease Control and Prevention)

("Impact of Global Warming")

Include the complete citation at the end of your paper in a Works Cited section. References are organized by the author's last name in alphabetical (A-Z) order. Use an hanging indent to separate each list item. Check out more examples of citing online sources from the MLA Style Center. 

Journal Article

1. Author(s). Use the format Last Name, First Name Middle Name or Initial. If there are two authors, use and before the last author's name. If there are three or more authors, list only the first author followed by the phrase et al. (Latin for "and others") in place of the subsequent authors' names.

2. "Title of the Article." Include the title of a shorter work like an article in a journal in quotation marks and use headline-style capitalization.

3. Title of the Journal, Use italics for the title of a longer work like a journal and use headline-style capitalization.

4. vol. #, Include the journal volume number. 

5. no. #, If there is no additional number after the volume, only include the volume number.

6. Year,

7. pp. xxx-xxx. Include page number range if available. 

If accessed online or in a library database...

8. Database, Use italics for names of databases.

9. DOI, URL, or permalink. 

Toledo, David, et al. "Extent of Kentucky Bluegrass and Its Effect on Native Plant Species Diversity and Ecosystem Services in the Northern Great Plains of the United States." Invasive Plant Science and Management, vol. 7, no. 4, 2014, pp. 543-552. BioOne Complete, https://doi.org/10.1614/IPSM-D-14-00029.1.

Book

1. Author(s). Use the format Last Name, First Name Middle Name or Initial. If there are two authors, use and before the last author's name. If there are three or more authors, list only the first author followed by the phrase et al. (Latin for "and others") in place of the subsequent authors' names.

2. Title of the Book. Use italics for the title of a longer work like a book and use headline-style capitalization.

3. Edition. If there is an edition, use the format 1st ed., 2nd., etc. 

4. Publisher,

5. Year.

6. Database. If it is an eBook, include the name of the database in italics. 

7. URL or permalink. If the book is available online. 

Richtel, Matt. An Elegant Defense: The Extraordinary New Science of the Immune System, 1st ed. William Morrow, 2019. 

Book Chapter with Editors

1. Chapter Author(s). Use the format Last Name, First Name Middle Name or Initial. If there are two authors, use and before the last author's name. If there are three or more authors, list only the first author followed by the phrase et al. (Latin for "and others") in place of the subsequent authors' names.

2. "Title of the Chapter." Include the title of a shorter work like a chapter in quotation marks and use headline-style capitalization.

3. Title of the Book, Use italics for the title of a longer work like a book and use headline-style capitalization.

4. edited by, If there is one editor, use the format edited by First Name Middle Name or Initial (if any) Last Name. If there are multiple editors, use and before the last author's name.

5. Publisher,

6. Year,

7. pp. xxx-xxx. Include the chapter page numbers.

8. Database, If it is an eBook, include the name of the database in italics.

9. URL or permalink. If the database is available online. 

Khan, Junaid S., et al. "Parasites of Seabirds: A Survey of Effects and Ecological Implications." Advances in Marine Biology, edited by Charles R. C. Sheppard, Academic Press, 2019, pp. 1-50. ScienceDirect, https://uofl.on.worldcat.org/oclc/1105199276.  

Website

1. Author or organization. Use the format Last Name, First Name. If there is no individual author, use the organization responsible for the work. When a work is published by an organization that is also the author, begin the entry with the title of the page. 

2. "Title of Page, Section, or Document." Use quotation marks and headline-style capitalization. 

3. Publisher, This is usually the name of the website or organization responsible. 

4. Accessed Day Month Year, Date of publication or last modified date. If there is no date, you can optionally include Accessed Day Month Year.

5. URL.

"A comprehensive list of common wild mushrooms in Kentucky." Healing Mushrooms, Accessed 16 February 2023, https://healing-mushrooms.net/kentucky.