Citation styles are formats and rules established and modified by institutions and associations of scholars in various academic disciplines. Style guides contain comprehensive guidelines that cover most citation situations. Preferred citation styles vary across fields and disciplines.
Check with your professor to make sure you use the citation style that they require. And whatever style you choose, be consistent! The Purdue OWL Research and Citation Resources Guide is a general guide that summarizes and provides basic examples of all of the styles listed here, and is a good place to get an overview.
Quickly generate a citation or reference list in any citation style by entering a URL, ISBN, DOI, PMID, arXiv ID, or title into the search box, or entering your citation elements.
Use the cite feature in Google Scholar to generate a citation. Search using the title of your source and click "cite under the item summary. Always double check database generated citations for accuracy.