If your instructor asks you to format the paper according to CMS, it refers to Chicago Manual of Style. This citation style has two different systems, the Notes-Bibliography System (NB) and Author-Date System.
The choice between these two systems depends on the subject and nature if the sources you want to cite. Different scholars prefer a different system. For this style, you present bibliographic information in the notes and often, in a bibliography. It accommodates various sources including the vague that will be less appropriate for author author-date system.