The student has quoted from a fact sheet titled Fracking in California: Questions and Concerns, issued by the Climate Law Institute of the Center for Biological Diversity. The student accessed the fact sheet online at http://www.biologicaldiversity.org/action/toolbox/fracking/pdfs/CAFrackingFactsheet_May2013_2.pdf. It is undated.

Center for Biological Diversity, Climate Law Institute. (n.d.). Fracking in California: Questions and concerns [Fact sheet]. Retrieved from http://www.biologicaldiversity.org/action/toolbox/fracking/pdfs/CAFrackingFactsheet_May2013_2.pdf

Center for Biological Diversity, Climate Law Institute. Fracking in California: Questions and concerns. Retrieved from http://www.biologicaldiversity.org/action/toolbox/fracking/pdfs/CAFrackingFactsheet_May2013_2.pdf

In APA style, the abbreviation “n.d.” is used for a source that is undated. The label “Fact sheet” is given in brackets to identify the type of source.