Caleb S.
Caleb S.

ACS Citation Made Easy: A Complete Guide for Everyone

16 min read

Published on: Mar 18, 2024

Last updated on: Mar 28, 2024

ACS Citation

Developed by the American Chemical Society, the ACS citation style is considered as the standard citation format for academic writing in Chemistry.

Students, researchers, and scholars from the Chemical field need help to cite papers accurately. This is why a standalone citation style was necessary for people belonging to the academic field of Chemistry.

If you’re on the same page regarding citation styles, don’t worry, this blog will help you perfect your ACS-styled paper.
In this ACS style guide, you’ll find valuable help for creating in-text citations, along with formatting the references for different sources at the end of your paper. 

Let’s get started!

What is the ACS Citation Style?

As mentioned before, the ACS style is primarily used for individuals who craft academic papers that are related to Chemistry.

In the ACS format, you have to incorporate the in-text citations within your text first, then list the corresponding reference entries at the end. 

However, unlike some other style guides (e.g., APA or MLA), the ACS style doesn't extensively cover the complete paper format. The format for margins, font styles, or overall document structure depends on the specific requirements of the journal you’re submitting your paper to. 

The latest edition of the ACS Guide to Scholarly Communication is the 3rd Edition. 

Let’s break down the in-text citation format first, then we’ll move on to the reference lists.

ACS In-Text Citation

For citing sources in-text, there are 3 ways you can use the ACS citation format. 

  • Using superscript numbers 2
  • Using parenthetical numbers in italics (2)
  • Using the author’s last name and the year of publication in parentheses (Mark, 2020)

Let’s break down each in-text citation style one by one.

Citing In-Text Using Superscript Numbers 

For ACS citation in-text, the superscript number method is designed for printed publications, where you utilize smaller superscript numbers. This method is preferred because it consumes less space and doesn’t distract the reader much. 

You can choose whether to place the superscript number at the end or within sentences.

ACS In-Text Citation Example: 

In their recent publication, Garcia and Patel 1 discussed the implications of climate change on agriculture.

The application of nanotechnology in medicine has shown promising results 2.

Utilizing Parenthetical Numbers for In-Text Citation 

The second most common in-text citation style is the italicized parenthetical numbers. This is commonly used in online ACS journals and manuscripts. Just use an italicized number in parentheses in between the sentences or at the end of the sentence. 

This style is a good fit for online journals because, for the readers, it is easier to click on the parenthetical number to view the full reference. 

For Example:

The synthesis of graphene nanosheets demonstrated exceptional conductivity, opening new possibilities for electronic devices (CuO nanocomposite) (4).

Nanoparticles of silver (Ag) have exhibited antimicrobial properties, revolutionizing medical applications (6).

Using the (Author-Date) System 

Another way to cite sources within your document’s text is to use the author-date system. Simply use the author's name and the year of publication in parentheses. Something to note here is that this in-text citation style is not practiced as much as the other two standards. 

For Example:

The groundbreaking work by Anderson (2017) on photocatalysis in organic synthesis highlighted its potential in green chemistry practices.

Recent investigations (Brown et al., 2021) into sustainable energy sources emphasized the role of nanomaterials in enhancing solar cell efficiency.

Let’s take a look at some tips for in-text ACS citations.

Handy Tips for In-Text Citation In ACS Citation

Follow these guidelines for error-free ACS referencing in your text:

  • Stick to a single in-text citation method and stay consistent throughout your document
  • Integrate references logically into your text to maintain a seamless flow
  • Start numbering your references from “1” and keep the numbering consecutive across the paper, including tables and figures
  • Avoid assigning a new number if a reference is repeated; use the original number
  • When citing multiple references at the same location, list numbers in ascending order, separated by commas (without spaces in superscript format, and with spaces in line format).

Example: “…in the literature1, 2, 3-5”
Example (inline format): “…in the literature (1, 2, 4-6)”

These tips guarantee a structured and accurate ACS in-text citation style in your writing.

After learning how to use in-text citations, we’re moving on to the reference lists of the bibliography section. 

How to Format ACS Citation Bibliography? 

The references used in the bibliography section of your ACS-styled paper will correspond to the in-text citations you used earlier.

Here are the general guidelines for reference list entries:

  • Begin the references list on a new page to separate it from the main text
  • Center or left-justify the word “References” at the top of the page for visual clarity
  • Utilize a hanging indent for each reference entry, indenting all lines except the first
  • List authors' last names followed by their initials without spaces. Separate multiple authors with commas
  • Italicize the titles of books, journals, or any complete works
  • For articles, include the journal title in italics, the publication year in bold, the volume number in italics, and the inclusive page numbers
  • For online sources, always provide the DOI (Document Object Identifier)

For numerical in-text citations (parenthetical or superscript), organize the corresponding references numerically. 

For Example: 

  1. Anderson, A.
  2. Armstrong, H.
  3. Allen, S.

For author-date in-text citations, arrange references in alphabetical order, by the last name of the first author.

For Example:

  1. Allen, S.
  2. Anderson, A.
  3. Armstrong, H.

In this example, references are alphabetically arranged based on the last names of the first authors.

ACS Citation References: Examples for Different Sources

Here are the reference examples for various sources in the ACS format. 


Author, A.; Author, B. Book Title, 2nd ed.; Publisher: Location, Year; Volume, pp 100-115.


Fisher, R.; Turner, K. Inorganic Chemistry: Advanced Concepts, 3rd ed.; Springer: Boston, 2019; pp 120-135.

ACS Citation: Book Chapter

Author, A.; Author, B. Title of Chapter. In Title of Book, 2nd ed.; Series Information, Vol. 3; Publisher, Year; pp 100-115. DOI or URL.


Reynolds, S.; Foster, J. Emerging Trends in Catalysis. In Innovations in Chemistry, 2nd ed.; CRC Press, 2022; pp 145-160. DOI: 10.1234/5678

For An Edited Book

Title of Book, 3rd ed.; Editor, A.; Editor, B., Eds.; Series Information (if any); Publisher, Year. DOI or URL.


Advancements in Biochemical Sciences, 4th ed.; Peterson, L.; Turner, M., Eds.; Oxford University Press, 2023. DOI: 10.9876/5432

For A Book in Series

Author, C.; Author, D. Title of Chapter. In Title of Book; Editor, X.; Editor, Y., Eds.; ACS Symposium Series 1234; American Chemical Society, 2018; pp 200-215. DOI or URL.


Wright, E.; Turner, M. Nanotechnology Innovations. In Nanoscience Breakthroughs; Peterson, J.; Harris, P., Eds.; ACS Symposium Series 5678; American Chemical Society, 2019; pp 180-195. DOI: 10.5555/12345678

For E-Books 

Author, C.; Author, D. Book Title [Online]; Series Information; Publisher: Place of Publication, Year; Volume, Pages Used. URL (accessed Month Day, Year).


Harrison, J.; White, L. Chemical Kinetics: Advanced Applications [Online]; Cambridge University Press: Cambridge, 2021. (accessed Mar 15, 2022).

For an Edited E-Book 

Author of Part, A. A.; Author of Part, B. B. Title of Chapter or Part. In Title of E-book: Subtitle of E-book; Editor, A. A., Editor, B. B., Eds.; Publisher, Year; pp page numbers. Internet address (accessed Year-Month-Day). Or DOI.


Morgan, K. A.; Turner, M. Nanoscale Applications in Medicine. In Advances in Nanomedicine: Current Trends; Peterson, L.; Harris, P., Eds.; Wiley, 2022; pp 95-110. (accessed 2023-06-01).

For Encyclopedia Articles 

Title of Article. In Title of Encyclopedia, Edition; Publisher, Year; Vol. Volume, pp Page Range.


Chemical Bonding. In Encyclopedia of Chemistry, 3rd ed.; Academic Press, 2022; Vol. 2, pp 150?165.

For Magazine or Newspaper Articles

Author, X.; Author, Y. Title of Article. Title of Periodical, Complete Date, pp 20-25.


Fisher, M.; Turner, K. Developments in Sustainable Energy. EcoTech Magazine, June 2022, pp 18-22.

For Scholarly Journal Article (Accessed from the Internet) 

Author 1; Author 2; Author 3; etc. Title of Article. Journal Abbreviation [Online], Year, Volume, Issue, Page Range. DOI or URL (accessed Date).


Wright, A.; Turner, R. Nanoparticle Applications in Drug Delivery. J. Nanomed. [Online], 2018, 10(4), 320-330. (accessed Feb 20, 2023).

Scholarly Journal Article (Library Database) 

Author, G.; Author, H. Title of Article. Journal Abbreviation [Online], Date, Pages. Database Name. Complete URL of the database (accessed date).


Ward, S.; Turner, L. Advances in Biotechnology. Bio Insights, June 10, 2020, p 45. PubMed. (accessed June 1, 2020).

Scholarly Journal Article (Printed)

Author(s). Title of Article. Journal Abbreviation, Year, Volume, Page Range.


Parker, J. R.; Turner, M. Recent Advances in Organic Synthesis, J. Chem. Soc. 2024, 48, 180-192.

For Legal Documents

Issuing Body, Title of the Document. Title of the Larger Publication or Manual, Edition number, rev. Revision details, Publication Date, URL (if available) (accessed Date in YYYY-MM-DD format).


Environmental Protection Agency, Clean Air Act - Section 112 Hazardous Air Pollutants. Code of Federal Regulations (CFR), Title 40, Part 63, Edition 2021. (accessed 2022-06-15).

If you’re accessing a legal document online:

Environmental Protection Agency, Clean Air Act - Section 112

Hazardous Air Pollutants. Code of Federal Regulations (CFR),

Title 40, Part 63, Edition 2021.


pt40.13.63&rgn=div5#se40.13.63_1800 (accessed 2022-06-15)

ACS Citation Format for Websites 

Author or Organization (if any). Title of Site. URL (accessed YYYY-MM-DD).


National Institute of Sustainable Chemistry. Green Chemistry Practices. (accessed 2023-06-15).

For Online Documents

Author 1; Author 2; et al. Title of Document. Title of Site or Organization, date. URL (accessed YYYY-MM-DD).


Jones, A.; Turner, B.; et al. Recent Developments in Environmental Chemistry. Green Chemistry Consortium, 2023. (accessed 2023-06-01).

For Blog Posts 

Author 1; Author 2; et al. Blog Post Title. Blog Title. Title of Site or Publisher (if any), date. URL (accessed YYYY-MM-DD).


Fisher, M.; Turner, K.; Parker, J.; et al. Advances in Renewable Energy Technologies. EcoTech Blog. EcoTech News, May 20, 2024. (accessed 2024-06-01).

ACS Citation: Multiple Authors

When there are more than two authors, add ‘et al.’ after the first two authors.


Smith et al. (18)

For Lab Manual Papers 

Author 1; Author 2; etc. Title of Book, Edition Number; Publisher: Location, Year; Volume number, pp Pages Used.


Johnson, A. Organic Chemistry Laboratory Handbook; University of ABC: Somewhere, USA, 2020; p 50.

For Print Reference Works 

Author, A. A., Author, B. B. Article Title. In Title of Reference Work, Edition Information; Editor, E. E., Eds.; Publisher, Year; Volume, pp Pagination.


Brown, S. R.; Turner, M. Spectroscopy Advancements. In Encyclopedia of Analytical Chemistry, 5th ed.; Harris, P. Q., Smith, J. R., Eds.; Wiley: New York, 2022; Volume 4, pp 220-235.

For Online Reference Works

Author, A. A., Author, B. B. Article Title. In Title of Reference Work, Edition Information; Editor, E. E., Eds.; Publisher, Year. DOI or URL.


Anderson, S. M.; Turner, R. Sustainable Chemistry Methods. In Encyclopedia of Sustainable Chemistry, 4th ed.; White, L. R., Ed.; Springer, 2021. (accessed 2023-06-15).

For Thesis Documents

Author. Title of Thesis. Level of Thesis, Degree-Granting University, Location of University, Date of Completion.


Parker, J. R. Nanoparticles in Medical Imaging. Ph.D. Dissertation, University of XYZ, Somewhere, USA, 2023.

For Patents 

Patent Owner 1; Patent Owner 2; etc. Title of Patent. Patent Number, Full Date.


Stellar, A.; Galaxy, M.; Innovative Quantum Gadgetry. Patent US 8,765,432 C1, November 7, 2021.

For Meetings and Conferences 

For one of the said sources, follow the below format:

Author 1; Author 2; etc. Title of Presentation. In Title of the Collected Work, Proceedings of the Name of the Meeting, Location, Full Date(s); Editor 1, Editor 2, etc., Eds.; Publisher: Place of Publication, Year; Abstract Number, Pagination.


Quasar, Z.; Nebula, A. Revolutionizing Quantum Computing.In Proceedings of the Celestial Technologies Symposium, Star City, Mars, November 15-17, 2022; Orion, S., Draco, L., Eds.; Cosmic Press: Mars, 2022; Abstract Number: CP-5678, pp 12-25.

When you want to cite the abstract of the meeting or the conference follow the below format:

Author 1; Author 2; Author 3; etc. Title of Presentation. Title of the Collected Work, Proceedings of the Name of the Meeting, Location, Full Date(s); Publisher: Place of Publication, Year; Abstract Number, Pagination.


Aether, C.; Lyra, N. Unraveling Mysteries of Dark Matter. Abstracts of the Galactic Physics Conference, Exoplanet Observatory, Alpha Centauri, April 3-5, 2023; Stellar Insights: Alpha Centauri, 2023; Abstract Number: SI-123, p 18.

For Technical Reports and Bulletins 

Author 1; Author 2; etc. Title of Report or Bulletin; Technical Report or Bulletin Number; Publisher: Location, Date; Pagination.


Harper, A.; Reed, S. Innovative Solutions for Water Conservation; Technical Report 5432; Environmental Solutions Research Center: Los Angeles, CA, May 15, 2023; 35 pages.

For Computer Software 

Author 1; Author 2; etc. Program Title, version, or edition; Publisher: Location, Year.


Garcia, A.; Taylor, R. CodeGenius Deluxe, Edition 5.2; InnovateTech Solutions: Austin, TX, 2023.

With the help of these examples, you can list the references for any source type in your document. Now, let’s take a look at some common mistakes that people make while crafting citations in the ACS format. 

Common Mistakes to Avoid in the ACS Reference Style

Here are some of the most common mistakes that you should be careful of: 

    • Mixing Citation Styles: Stick to one method, be it numbers or author-date, for a neat look throughout your paper
    • Forgetting Formatting Rules: Mind the details like italics for certain titles and proper punctuation. Italics are for journals and books, while quotes suit articles and chapters
    • Overlooking DOI or URL: Don't skip adding a DOI or URL for online sources. It helps readers access the material easily
    • Comma Confusion: Be careful with commas, especially when listing authors or elements. Follow ACS style for accurate punctuation
    • Ignoring Abbreviations: Use standard journal abbreviations. ACS provides a list for reference
    • Messing Up Numbering: Keep a logical sequence in numbering your references, including tables and figures
    • Page Range Blunders: Format page ranges properly with an en dash (–) and no spaces
    • Skipping Publication Details: Include all crucial details – author(s), title, source, publication year, etc. Incomplete citations create confusion
    • Superscript Slip-ups: If using superscript numbers, place them after punctuation. Incorrect placement disrupts sentence flow
    • Use Et al. Properly: never italicize, “Et al.” when listing sources that contain more than three authors

In summary, understanding ACS Citation is essential for students and researchers. This guide has presented you with straightforward rules and examples to ensure your citations are accurate. If you still find citations challenging, consider getting help.

Give our citation machine a shot – select your citation style, input the necessary details, and let our ACS referencing generator manage the rest. 

Explore ACS citation machine for effortless assistance with your referencing needs today!

Caleb S.


Caleb S. (Mass Literature and Linguistics, Masters)

Caleb S. is an accomplished author with over five years of experience and a Master's degree from Oxford University. He excels in various writing forms, including articles, press releases, blog posts, and whitepapers. As a valued author at, Caleb assists students and professionals by providing practical tips on research, citation, sentence structure, and style enhancement.

Caleb S. is an accomplished author with over five years of experience and a Master's degree from Oxford University. He excels in various writing forms, including articles, press releases, blog posts, and whitepapers. As a valued author at, Caleb assists students and professionals by providing practical tips on research, citation, sentence structure, and style enhancement.

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