The range of formal and informal writing in the biological sciences encompasses:
In the sciences, the primary literature:
Examples of primary literature in the sciences include:
Grey Literature: Dissertations and theses, technical reports, conference presentations, and other documents are considered grey literature (or gray literature), defined by GreyNet as "multiple document types produced on all levels of government, academics, business, and [other] organization[s] in electronic and print formats. . .where publishing is not the primary activity of the producing body." Grey literature may have editorial or committee oversight, but does not necessarily undergo the process of peer review. Nonetheless, it may have significant scientific value.
The secondary literature is a good place to start when you are investigating a new topic, because secondary sources:
Examples of secondary literature in the sciences include:
The tertiary literature:
Examples of tertiary literature in the sciences include: