The style manual published by the Council of Biology Editors (CBE)— Scientific Style and Format: The CBE Manual for Authors, Editors, and Publishers, 6th ed. —is the basic guide for most writing in the life sciences and medicine. In addition to extensive treatment of the conventions for scientific terminology, it presents two systems of documenting references: a name-year system similar to that of APA and a citation-sequence system, which uses superscript numbers in the text that refer to a numbered list of references. (Some scientific journals use some variant of one of these systems, such as citation numbers enclosed in parentheses in the line of text rather than above it; check with your instructor about the preferred citation system for your class.)
The major difference between the CBE system of numbered notes and that of The Chicago Manual is that the references in CBE are assigned a number by order of first mention in the paper and the number is repeated whenever that reference is cited in the paper. In general, the goal of the CBE style for entries in the reference list is to minimize the number of keystrokes made by the typist: there are no periods after initials; names of journals and publishers are abbreviated; neither italics nor quotation marks are used with titles of books, journals, or articles.