The Council of Science Editors (CSE) offers three systems of documentation. In all three systems, a reference list at the end of the paper provides all the information your reader needs to track down your sources. In-text references in your sentences show your reader which sources support the claims and information of that sentence.
The systems differ in the details of how they format in-text references and how they organize the reference list. For more information about each system, click on the appropriate link below:
Example from Charkowski (2012):
Despite this, there has been significant progress in modeling gene regulation in SRE, including mathematical models of virulence 75 and examination of gene expression at the single cell level 87,158,159,166.
Example from Newbury (2013):
These interactions have been implicated in many systems, including small molecules 4, peptides 5, proteins 6, peptoids 7, and nucleic acids 8.
Example from Wattiaux (2005):
Milk urea nitrogen can be used as an indicator of the adequacy of protein and the balance between energy and protein in lactating dairy cow diets (Broderick and Clayton 1997; Wattiaux and Karg 2004a) and as a predictor of urinary nitrogen excretion (Kauffman and St Pierre 2001; Kohn et al. 2002; Wattiaux and Karg 2004b).
For a class paper, check to see if your instructor prefers one of these systems. For a journal article, check the journal's instructions to authors to find out which system to use.