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***Citation Styles: ACS

ACS Style Guide

ACS Style Guide, 3rd Edition
Effective Communication of Scientific Information

Editor(s): Anne M. Coghill, Lorrin R. Garson
Publication Date (Print): June 01, 2006
Copyright © 2006 American Chemical Society

Part 1. Scientific Communication

Chapter 1. Ethics in Scientific Publication

1-1: Ethical Guidelines to Publication of Chemical Research

Chapter 2. Scientific Papers

Chapter 3. The Editorial Process

3-1: Proofreaders’ Marks

Chapter 4. Writing Style and Word Usage

Chapter 5. Electronic Submission of Manuscripts Using Web-Based Systems

5-1: Online Submission at Selected Scientific Publishers and Research Grant Agencies
5-2: Key Features of Selected Online Submission Systems

Chapter 6. Peer Review

Chapter 7. Copyright Basics

Chapter 8. Markup Languages and the Datument

8-1: The IUPAC International Chemical Identifier, InChI

Part 2. Style Guidelines

Chapter 9. Grammar, Punctuation, and Spelling

9-1: Recommended Spelling List

Chapter 10. Editorial Style

10-1: Computer and Internet Terms
10-2: Abbreviations, Acronyms, and Symbols

Chapter 11. Numbers, Mathematics, and Units of Measure

11-1: The International System of Units (SI).

Chapter 12. Names and Numbers for Chemical Compounds

12-1: End-of-Line Hyphenation of Chemical Names
12-2: Representation of Combinatorial Chemistry
12-3: CAS Registry Numbers

Chapter 13. Conventions in Chemistry

13-1: Symbols for Commonly Used Physical Quantities
13-2: The Crystallographic Information File

Chapter 14. References

14-1: CASSI Abbreviations for the 1000+ Most Commonly Cited Journals
14-2: A Sample CASSI Entry

Chapter 15. Figures

Chapter 16. Tables

Chapter 17. Chemical Structures

Chapter 18.  Selected Bibliography


In Text Citations

ACS suggests citing references in text in one of three ways.  
Consult your syllabus or ask your professor which is preferred.

By superscript numbers:

Example 1 Oscillation in the reaction of benzaldehyde with oxygen was reported previously.3

Example 2 Frink3  reported oscillation in the reaction of benzaldehyde with oxygen.

By italic numbers in parentheses:

Example 1 Oscillation in the reaction of benzaldehyde with oxygen was reported previously (3).

Example 2 Frink (3reported oscillation in the reaction of benzaldehyde with oxygen.

By author name and year of publication in parentheses inside the punctuation (author-date system):

Example 1 Oscillation in the reaction of benzaldehyde with oxygen was reported previously (Frink et al., 2005).

Example 2 Oscillation in the reaction of benzaldehyde with oxygen was reported previously by Frink and colleagues (2005).

For in text citations for items with:

Two authors - provide the last name of both authors, separated by the word "and"

(Nahasapeemapetilon and Alenno, 2005).

More than two authors - provide the last name of only the first author listed, and then "et al."

(Mollman et al., 2012).

Note: In text citations are different from the reference list at the end of the paper. In the reference list, all author names should be provided and separated by semicolons.

Reference List (Works Cited)

Collect all references at the end of the manuscript...

  • in numerical order if cited by number.  If a reference is repeated, do not give it a new number; use the original reference number. ***use for CHEM 4160 with Dr. Ray***
  • in alphabetical order if cited by author

Journal Article

Author 1; Author 2; Author 3; etc. Title of Article. Journal Abbreviation YearVolume (Issue), Inclusive Pagination.
Caruso, R.A.; Susha, A.; Caruso, F. Multilayered Titania, Silica, and Laponite Nanoparticle Coatings on Polystyrene Colloidal Templates and Resulting Inorganic Hollow Spheres. Chem. Mater. 2001, 13, 400-409.

- Bold for year, italic for journal title and issue number

- Use the CASSI abbreviation for the journal title

- Capitalize all main words in the article title (excluding connecting words like "and", "or", "on", etc.)


Patent Owner 1; Patent Owner 2; etc. Title of Patent. Patent Number, Date.
Sheem, S. K. Low-Cost Fiber Optic Pressure Sensor. U.S. Patent 6,738,537, May 18, 2004.

General Website

Author (if any). Title of Site. URL (accessed Month Day, Year).
ACS Publications Division Home Page. (accessed Nov 7, 2017).
Include the date you accessed a website, since websites often change over time


Author 1; Author 2; Author 3; etc. Book Title, Edition Number; Series Information (if exists); Publisher: Place of Publication, Year; Volume Number, Pagination.
Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coordination Compounds, 6th ed.; Wiley: Hoboken, NJ, 2009; pp 23-32.

- Italics for book title, but year is not bolded (different from journal article)

- pages are indicated with "pp" (different from journal article)

Book Chapter (from an edited book)

Nishiyama, H.; Shiomi, T. Reductive Aldol, Michael, and Mannich Reactions. In Metal Catalyzed Reductive C-C Bond Formation : A Departure from Preformed Organometallic Reagents; Krische, M.J., Ed.; Springer: Berlin, 2007; pp 105-138.


Ghosh, A. Arrow Pushing in Inorganic Chemistry: A Logical Approach to the Chemistry of the Main-Group Elements. John Wiley & Sons, Incorporated: Hoboken, NJ, 2014: pp 201. (accessed January 5, 2017).

Download ACS Style

Download for ‚ÄčEndNote

ENS EndNote Style file.

Save the file to your EndNote program folder. When you open your EndNote library, use the pull-down menu to choose ACS style.

Download for Zotero 

CSL Citation Style file

Download for Mendeley

CSL Citation Style file - same file as Zotero

CASSI Abbreviations

Et Al.

What does et al. mean?

Often seen in reference lists for a variety of different styles, et al. is a common abbreviation from the Latin "et alia" (gender neutral), "et alii" (masculine), or "et aliae" (feminine). It means "and others", or "and all the rest".

When is it used?

Et al. is used with a very long list of authors to indicate that there are more contributors not specifically listed. While the ACS Style Guide generally recommends listing all authors (Chapter 14, page 291), some journals ask for only a certain number of listed authors before using et al., so check the requirements of the publication.

Where is the punctuation?

Since only "alia" is abbreviated, it gets the period. Putting the period after "et" is a common mistake.

This Grammarly post does an illustrated explanation.