In the sciences, each journal establishes its own citation format, to which all authors are expected to conform.  Some of these are similar to the APA format; few are similar to MLA.  A few of the straightforward ones are shown below.  Whichever format you choose, BE CONSISTENT THROUGHOUT THE PAPER.

For the purposes of this class, you may use any format that you find used in a scientific journal if the following basic requirements are met.  The citation must include
The reference or sources cited list should either be numbered in order of citation (I don't recommend this because it can be problematic when you edit) or alphabetic by author's last name recommended.  Citation format within the text depends on which you choose.

The convention for citing references within the body of a paper is that when specific information from a source is used, that source is cited either by number or by author last name, date in ( ).  For example,

You must use correct and complete citations in all written work except in-class exams (Schmeidler, 2008)

Schmeidler, K.T. 2008. personal communication

If there are more than one citation with the same author and date, then use a, b, etc. to distinguish among them.

Examples of acceptable citation formats (examples are for journals)  [other formats may be acceptable if they include all the information, and are used in some journal] :

Schmeidler-Sapiro, K.T., Ratnoff, O.D., and Gordon, E.M. 1991. "Mitogenic Effects of Coagulation Factor XII and Factor XIIa on HepG2 Cells." Proc Natl Acad Sci 88:4382-4385.

Schmeidler-Sapiro, K.T., Ratnoff, O.D., and Gordon, E.M.  "Mitogenic Effects of Coagulation Factor XII and Factor XIIa on HepG2 Cells." Proc Natl Acad Sci 88:4382-4385. 1991.

Schmeidler-Sapiro, K.T., Ratnoff, O.D., and Gordon, E.M.  Proc Natl Acad Sci 88:4382-4385. "Mitogenic Effects of Coagulation Factor XII and Factor XIIa on HepG2 Cells."  1991.