Published by opencolleges.edu.au :
Those are the four main styles used when writing professionally or academically. Students will need to use one of these standard styles, so it’s important that you at least have a familiarity with them.
That’s why we created this webpage, which pulls together style guide resources from all over into one convenient place and gives you the information you really need to know.
Modern Language Association (MLA) Resource Guide
American Psychological Association (APA) Resource Guide
Chicago / Turabian Resource Guide
Council of Science Editors Style (CSE) Resource Guide