Citing Sources in All Disciplines
Your teacher will tell you which style to use for each course.
The Difference in Documentation Styles by Subject
Online Writing Lab: Research and Citation

Databases and electronic encyclopedias will create a citation for you in a variety of styles!
Documentation Styles
Documenting Social Media
Documenting Canadian Government Publications
Google Docs now includes a citation tool which lets you add your citations into your document very easily. Go to Tools > Citations. Select the citation style you need (MLA, APA, or Chicago are available) then click + Add citation source. You have to enter your sources, there is no way to import from a citation creator. Once you have added a source, you can create an in-text citation, and eventually create your bibliography.
Other Citation Generators
Purdue OWL
BibMe
Earl of March Library Documentation and Notetaking Tools