When you are writing your paper, you will need to reference the sources that you have used to ground your work. In text, references are most commonly cited using a superscript number (see the How to cite references in text box below for other options). References in text are numbered sequentially. Also, if a reference appears more than one, it does not receive a new number.

The reference list appears at the end of your document. It is ordered numerically. Different types of sources (e.g. books, journal articles, etc.) are cited differently. See the How to format a reference list box below for information on how to cite articles, books, and online sources.

For citing references within text, use a superscript number. If the citation applies to a whole sentence, the superscript should appear outside the punctuation:

The median concentration of Pb in Chicago soils is 198 mg/kg.¹

For making authors names part of the sentence, include the superscript within the cited information:

Cannon and Horton¹ reported that the median concentration of Pb in Chicago soils is 198 mg/kg.

This is the most common style for ACS journals. For instance, it is used by the Journal of the American Chemical Society, Organic Letters, Organometallics, and Inorganic Chemistry.

Articles

• Articles in scientific journals:

  Cannon, W.F.; Horton, J.D. Soil Geochemical Signature of Urbanization and Industrialization - Chicago, Illinois, USA. Appl. Geochem. 2009, 24, 1590-1601.

  Article titles are not considered essential, so you may write the same reference without the title:

  Cannon, W.F.; Horton, J.D. Appl. Geochem. 2009, 24, 1590-1601.

  Journal names with more than one word are abbreviated. Check CAS Source Index (CASSI) por the correct abbreviation! 

Books

• Books without editors (i.e. the entire book was written by one or more authors and all the authors collaborated on the whole book).

  Bitton, G. Wastewater Microbiology, 4th ed.; John Wiley & Sons: Hoboken, 2010.

• Books with editors (i.e. different authors wrote different parts or chapters of the book).

  Hermann, B.G.; Dornburg, V.; Patel, M.K. Environmental and Economic Aspects of Industrial Biotechnology. In Industrial Biotechnology: Sustainable Growth and Economic Success; Soetaert, W., Vandamme, E. J., Eds.; Wiley-VCH: Weinheim, 2010; pp. 433-455.

  For citing only the book without the chapter information:

  Industrial Biotechnology: Sustainable Growth and Economic Success; Soetaert, W., Vandamme, E. J., Eds.; Wiley-VCH: Weinheim, 2010.

• Books in series:

  Novel Solutions to Water Pollution; Ahuja, S.; Hritovski, K., Eds.; ACS Symposium Series 1123; American Chemical Society, Washington, DC, 2013.

Online sources

• Websites:

  Environmental Protection Agency. http://www.epa.gov (accessed Nov 7, 2013).