Chicago (CMS) style is commonly used style to cite sources within the fields of literature, history, the arts, and the sciences. 

Use the Notes-Bibliography system for literature, history and the arts.  Use the Author-date system for the sciences.

For a more detailed explanation of how to use Chicago style, see the online version of the Chicago Manual of Style.

The 17th edition is the most recent version of the Chicago style of writing and offers two styles of writing:

1. Notes-Bibligraphy system - most commonly used in literature, history, and the arts. 
2. Author-Date system - most often used in the sciences.