The Chicago Manual of Style actually presents two different styles of documentation and citation: the humanities style, which uses notes and a bibliography, and the author-date system. As the name suggests, humanities style is more common for writing in the arts, literature, and related disciplines, while author-date is found more frequently, though not exclusively, in the natural and social sciences. "Turabian" is a version of the humanities style intended for student papers found in Kate Turabian's A Manual for Writers of Term Papers, Theses, and Dissertions.
