This link will take you to the latest version of the APA Publication Manual (i.e., APA 7), which released in October 2019. Check with your professor to see if you should use this 7th edition or the earlier 6th edition of the APA
MLA style is most commonly used to cite sources within the language arts, cultural studies, and other humanities disciplines. This resource, revised according to the 8th edition of the MLA manual, offers examples for the general format of MLA research papers, in-text citations, and the Works Cited page.
The Chicago Manual of Style (CMOS) is most commonly used by those working in literature, history, and the arts. This resource, revised according to the 17th edition of CMOS, offers examples for the general format of CMOS research papers, footnotes/endnotes, and the bibliography.
Instead of long URL's and permalinks, citation styles such as APA now use DOI's or Digital Object Identifiers. They provide a stable place to retrieve documents.
A Manual for Writers of Research Papers, Theses, and Dissertations, Eighth Edition by 