Professionals -- and students -- use a particular citation style to standardize their sources of information to help the reader. Once the reader knows the italicized title in the citation is the journal title, for example, they can then interpret other elements of the citation. One citation style should be followed throughout, i.e., the in-text citations and the references list at the end of the research product.
Only list those sources referred to within your text. Provide as much information as it takes to locate the work; generally that includes the author(s), publication date, title of the work, and publisher, though more information must be given for journal articles, electronic sources (e.g., Web pages), etc.
Still can't figure out how to cite a source? Try the APA Style and Grammar Guidelines or the APA Style blog, which answers questions about atypical sources. Or consult the Excelsior Online Writing Lab (OWL) for more guidance.
Each version of a digital document receives a unique number, i.e., a DOI or digital object identifier.
Why is a DOI important to include in reference citations? Electronic articles can exist in many versions, which can make tracking articles tricky at times. In addition, corrections can be made in an electronic version with a simple updating of the file without any acknowledgement that the change has been made. All of these possibilities make it important to use the DOI of an article if it can be found so your reader can locate the version you have referenced.
CrossRef.org offers a free DOI lookup service if you cannot locate an article's DOI.