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ACS (American Chemical Society) style

The ACS style was developed by the American Chemical Society and is used for academic writing in chemistry.

ACS uses both numbered and author-date systems:

In-text citation:

References in the text should be cited in one of the two ways:

By number: either italic numbers in brackets, or superscript numbers numbered sequentially

If a reference is cited more than once, it does not receive a new number.

When citing more than one reference at a time, include reference numbers in increasing order separated by commas.

By author-date: surname and year of publication in brackets.

Reference list:

The list of references appears at the end of the paper in numerical order if cited by number or in alphabetical order if cited by author-date.

Use only the initials of the authors' given names. Use full stops and spaces between the initials. Last name comes first.

Here is an example that cites a book with one author using ACS style.

In-text citation (numbered)

Reference list

.....(1) or Neville (1) stated that .....

.....1 or Neville1stated that .....

1 Neville, C. The Complete Guide to Referencing and Avoiding Pagiarism, 2nd ed.; Open University Press: New York, 2010.

In-text citation (author-date)

Reference list

.....(Neville, 2010) or Neville stated that ..... (2010)

Neville, C. The Complete Guide to Referencing and Avoiding Pagiarism, 2nd ed.; Open University Press: New York, 2010.

Interactive referencing tools

The interactive tool below, created by University of Auckland library, is designed to provide you with examples of referencing for a range of resources. You will access these references by selecting from the menu until you get to the detailed information.

Quick guide and examples

The attached quick guides created by other institutions provide an overview of the ACS 3rd ed referencing style. In these documents you will find examples for different types of materials and details on specific variations of citations.

Other resources

Using generative artificial intelligence tools (e.g. Chat GPT)

ACS style guide

Bibliographic management software

Macquarie University has licences for two bibliographic management software packages:

 EndNote 20 for Windows

 EndNote 20 for Mac


You can use these Bibliographic referencing tools to maintain your references. They can also create bibliographies automatically in Word.

EndNote training is available for current postgraduates, higher degree researchers and staff.

You can contact your Faculty Librarian for a session.