See the website of the CEU Center for Academic Writing, particularly the following:
Because there is no one standard citation style used at CEU:
Academic organizations and some disciplines outline their own styles of how to cite sources and format research papers. You may have heard of or used some of the styles before.
Consult these print and online style guides for examples of citing sources in the text of your paper and in a bibliography or reference list. See also information about Using Zotero to Manage Your Sources.
MLA: Modern Language Association [Humanities]
APA: American Psychological Association [Social Sciences]
CMS: Chicago Manual of Style Online [various subjects]
ASA: American Sociological Association. [Sociology]
OSCOLA: The Oxford University Standard for Citation of Legal Authorities [Law]
The Bluebook [Law]