Citations MUST follow the practices of the Chicago Manual of Style or the abridgment generally referred to as “Turabian” (A Manual for Writers of Term Papers, Theses, and Dissertations by Kate Turabian et al.). You can find information on how to do this in those books or at the University of Wisconsin's Writing Center pages.
Please pay attention to “second citations,” or abbreviated citation format, which is a necessity (check my fn. 2, below, for a silly example which includes imaginary page numbers without the abbreviation “p”).
I will return to you any paper with either parenthetical references or incorrect numeration of notes/bibliography, and consider it late.