MLA
MLA Style is a system for documenting sources in scholarly writing and student research papers recommended by the Modern Language Association (MLA). It is most often used by the humanities (literature, art, philosophy)
APA
APA stands for American Psychological Association and is a common formatting style for essays and papers in the social, natural and behavioural sciences. (Socials, Science and Psychology)
CHICAGO
The Chicago style offers two systems fo citation: Author/Date and Notes/Bibliography. The NB system is most comonly used by those in the field of history. It involves citing sources using notes -footnotes-or endnotes- and most often, supplementing the information with a biblography.