*Chemistry

This page includes guidelines for two common citation styles, APA and ACS. 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

• ACS
  • In-text citations
  • References
• APA
  • In-text citations
  • References

This guide is a quick introduction to the American Chemical Society (ACS) Style for in-text citations and references. Be sure to consult chapter 4.3 of The ACS Guide to Scholarly Communication for full details on citing sources in ACS Style.

There are three ways to cite a reference in-text, in the body of your paper. Check with your professor to see which style is preferred. 

Superscript numbers

Include a superscript number for each sequential reference where you cited the information at the end of the sentence, or next to the authors' last name. 

Methods to control key interfacial chemistry include chemical functionalization and physical interactions for high-energy-density active materials in robust composite electrodes.¹

Gueon and colleagues¹ outline methods for controlling key interfacial chemistry such as chemical functionalization and physical interactions for high-energy-density active materials in robust composite electrodes.

To add a superscript in Word, highlight the number, then click on the superscript option in the Font settings.

Italic numbers

Include the number in parenthesis and italics for for each sequential reference where you cited the information at the end of the sentence, or next to the authors' last name. 

Methods to control key interfacial chemistry include chemical functionalization and physical interactions for high-energy-density active materials in robust composite electrodes (1). 

Gueon and colleagues (1) outline methods for controlling key interfacial chemistry such as chemical functionalization and physical interactions for high-energy-density active materials in robust composite electrodes.

Author name and year of publication

Include the last name of the author(s) in parenthesis followed by a comma and the year. Or, include the author(s) names narratively in the sentence and conclude with the year in parentheses. If there are two authors, use the word and. If there are three or more authors, use the abbreviation et al., which stands for "and others."

Methods to control key interfacial chemistry include chemical functionalization and physical interactions for high-energy-density active materials in robust composite electrodes (Gueon et al., 2023). 

Gueon et al. (2023) outline methods for controlling key interfacial chemistry such as chemical functionalization and physical interactions for high-energy-density active materials in robust composite electrodes. 

Include the complete citation at the end of your paper in a references section including the author(s), publication date, and publication information. 

If you used numerical superscript or italic numbers, list your references in numerical order at the end of your paper. If you used the author-date system, list your references in alphabetical order by the first author's last name. 

Use the following directions and examples to format these common types of sources. You can find more reference examples on ACS'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. with a semi colon between each author's last name. 

2. Title of the Article. Use headline style capitalization, meaning the first word and all main words are capitalized besides "less important" words like a, an, and, the, etc. 

3. Abbreviated Journal Title Include the abbreviation of the journal title in italics. Some journal abbreviations will be included with the article information, otherwise look up the abbreviation in a search engine or the CAS Source Index (CASSI) database. 

4. Year, Include the year of publication in bold. 

5. Volume number Include the volume number in italics. 

6. (Issue number), Include the issue number in parenthesis. If there is no issue number, include a comma after the volume number. 

7. Page range. Include the page range or article number. 

8. DOI: Include only the digital object identifier (DOI) string (not the https://) after DOI:.

Gueon, D.; Gonzalez, M. A.; Takeuchi, K. J.; Takeuchi, E. S.; Marschilok, A. C.; Reichmanis, E. Understanding Interfacial Chemistry Interactions in Energy-Dense Lithium-Ion Electrodes. Acc. Mater. Res 2023, 4 (2), 156-167. DOI: 10.1021/accountsmr.2c00198

Book

1. Author(s). List each author's last name and initials as Author, A. A.; Author, B. B.; Author, C. C. with a semi colon between each author's last name. 

2. Title of Book, Use italics and headline style capitalization, meaning the first word and all main words are capitalized besides "less important" words like a, an, and, the, etc. 

3. Edition; Use the abbreviated ed. 

4. Series, If any. 

5. Volume; If there are multiple volumes in the series, use Vol. 

6. Publisher, 

7. Year. 

8. DOI: If an ebook with a digital object identifier (DOI). Include only the DOI string (not the https://) after DOI:.

Hammond, C. The Basics of Crystallography and Diffraction, 4th ed.; International Union of Crystallography Texts on Crystallography, Vol. 21; Oxford University Press, 2015. DOI: 10.1093/acprof:oso/9780198738671.001.0001

Book chapter with editors

1. Author(s). List each author's last name and initials as Author, A. A.; Author, B. B.; Author, C. C. with a semi colon between each author's last name. 

2. Title of Chapter. Use headline-style capitalization, meaning the first word and all main words are capitalized besides "less important" words like a, an, and, the, etc. 

3. In Title of Book; Use italics and headline style capitalization. 

4. Editors Eds.; List each editors last name and initials as Author, A. A.; Author, B. B.; Author, C. C. with a comma between each author's last name and Eds. at the end.

5. Publisher, 

6. Year; 

7. pp page range. 

8. DOI: DOI: If an ebook with a digital object identifier (DOI). Include only the DOI string (not the https://) after DOI:.

Kulkarni, Y.; Kamerlin, S. C. L. Computational Physical Organic Chemistry Using the Empirical Valence Bond Approach. In Advances in Physical Organic Chemistry; Williams, I. H.; Williams, N. H. Eds.; Academic Press, 2019; pp 69-104. DOI: 10.1016/bs.apoc.2019.07.001

Website

1. Name of the web page. In italics and headline style capitalization, meaning all main words are capitalized besides "less important" words like a, an, and, the, etc. 

2. URL

3. (accessed year-month-day). 

ACS Publications Home Page. https://pubs.acs.org/ (accessed 2023-03-08). 

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