Chicago (or the closely related Turabian) style is a frequently used style for the discipline of philosophy. It allows you to use either footnote or parenthetical author-year citation -- ask your professor which (s)he prefers. There is a brief online guide to citation using the Chicago style at the University of Wisconsin Writing Center. The University of Georgia has produced a brief online guide to the Turabian style.
Ellis Library also has a copy of the latest edition of both guides in the Ready Reference section.
For graduate students, it's good to know how to search for dissertations in your field, both from MU and from other universities. MU librarians maintain a page showing available databases for doing this.