In-text references should immediately follow the title, word, or phrase to which they are directly relevant, rather than appearing at the end of long clauses or sentences. In-text references should always precede punctuation marks.

Name-Year (N-Y) system (end references are listed in alphabetic order)

In text example: By contrast, the several antisera that have been raised against Sp1, a defined RNA polymerase II transcription factor (Kadonaga 1986), stain exclusively the nucleus...

Note: If you mention the author in the running text of your paper, include only the year in the parenthetical citation:

Example: This conclusion is supported by Rubin and Smith (1990), who found that...

Multiple authors:  If two authors, list both. For more than two authors, list the first author then et al.

Example: In the classic experiment (Gass and Varonis 1984) showed that....

Example: Recent research (Munro et al. 2006) has shown that...

No author: Use the title (for long titles use the first few words followed by an elipsis): 

Example: Top fields of study for international students are business and engineering, followed by physical and life sciences, math and computer science, and social sciences (Open Doors 2010).

No date: For online sources if the publication year cannot be determined use the year of access. For print sources use [date unknown]:

Example: Claims were made (Smith [date unknown]) with regards to...