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ACS Referencing Style Guide Referencing Style Guide

When preparing an assignment or research paper, it is vital that you acknowledge the resources you have used:

  • Failure to do so constitutes plagiarism.
  • Readers need to be able to retrieve the source information you have used.

Your sources must be cited

  • in the text of your assignment or research paper (in-text citations) where you have referred to information obtained from a particular source.
  • in the list of references at the end of your assignment or research paper.

In-text Citations

Short citations included in the text of a research paper or assignment will enable your readers to find the full details of the source in the reference list.

Page numbers may or may not be included, depending on how specifically you have referred to the source. If you are using an electronic source that has no page numbers, you may use a paragraph number (abbreviation para.) to indicate to which part of the document you are referring.

When using the ACS Referencing Style, you may cite references within the text of your document in one of three ways:

  • By author name and year of publication in parentheses.
    • Example:
      • .... shown by the evidence (Black, 1997).
    • If there are two authors, join them with the word "and" e.g. (Smith and Green, 1996).
    • If there are more than two authors of a cited reference, use et al. e.g. (Platt et al., 2004).
  • By numbering.
    • With superscript numbers.
      • Example:
        • .... shown by the evidence2
    • With italic numbers on the line and in parentheses.
      • Example:
        • .... shown by the evidence (3)

Author name and year

Indirect quotations

If you paraphrase another author's ideas or research findings, integrate them as part of your text in your own words. When paraphrasing or referring to an idea contained in another work, you are not required to provide a location reference (page number), but may do so if appropriate.

Examples:

Hydrogen bonding can deactivate certain thiolates in these complexes (Maret, 2004).

Markham and Reczkowski (2003) stated that three signals were shown by the resulting complex.

Direct quotations

Use double quotation marks to enclose another author's words. A location reference (page numbers or paragraph numbers) must be provided. If your direct quotation is more than 40 words, indent the quoted section without quotation marks.

Example:

According to Maret (2004), this interaction is "a partnership in which sulfur imparts mobility on zinc and zinc modulates the chemical properties of sulphur" (p. 3306).

Citations from a secondary source

If you use an idea from an author cited by another author, use "as cited in". In the reference list at the end of your paper, list only the secondary source.

Examples:

Wilkar and Lippard (as cited in Maret, 2004, p. 3302) stated that these results indicate that the dissociated ligand is a nucleophile.

These results indicate that the dissociated ligand is a nucleophile (Wilkar and Lippard, as cited in Maret, 2004, p. 3302).

Citing more than one reference

You may cite more than one reference at the same place within the text of your document.

List the references alphabetically, according to the first author's name, followed by a comma and the year. Use a semi-colon to separate individual references.

Example:

.... the chemical compounds concerned (Adams, 1998; Dobbs and Steele, 2000; Mallard et al., 1995).

Numbering

In-text citations are represented either by superscript numbers or italicised numbers in parentheses.

Numbers in the text of your document will correspond with the appropriate reference in your list of references at the end of your document.

Examples:

Hydrogen bonding can deactivate certain thiolates in these complexes1

Hydrogen bonding can deactivate certain thiolates in these complexes (1).

Markham and Reczkowski2 stated that three signals were shown by the resulting complex.

Markham and Reczkowski (2) stated that three signals were shown by the resulting complex.

When using one of the numbering systems, footnotes would be used for any extra information. Specific page numbers could be included in the full reference at the end of the document.

Citing more than one reference

When citing more than one reference at the same place within your document:

  • Using the superscript number system:
    • List the numbers in ascending order and separate them by commas without spaces.
      • Example: .... as reported in the literature3,6,8
    • If the citations are part of a consecutive range of references, use a dash to indicate a consecutive range of three or more.
      • Example: .... indicated by the experimental evidence5-9,12
  • Using the italic number in parentheses system:
    • List the numbers in ascending order and separate them by commas with spaces.
      • Example: .... as reported in the literature (3, 6, 8).
    • If the citations are part of a consecutive range of references, use a dash to indicate a consecutive range of three or more.
      • Example: .... indicated by experimental evidence (5-9, 12).

The List of References/Bibliography

The list of references or bibliography will be at the end of your assignment or research paper, and will usually have the heading References.

References must be in alphabetical order if cited by author or in numerical order if cited by number.

Ensure that each resource you have used in the text of your assignment appears on your reference list.

The following elements must be included in a reference:

  • Author's or editor's name/s.
  • Title of the item.
  • Publication information:
    • For books, this will include place of publication and publisher's name - if two or more publisher locations are given, give the location listed first in the book.
    • For journal articles, this will include journal title, volume (or issue number if there is no volume) and page numbers.
    • For websites, give the full Web address (URL).
  • Publication year.

Works by the same author and published in the same year are distinguished by letters appended to the year. Example: If you are using two references by R. M. Smith, and both were published in 1998, one will bear the date 1998a and the other 1998b, and in-text citations will reflect this.

Note: Reference electronic books and online journal articles in the same way as print resources unless otherwise specified.