Information gathered from any source - books, journals, films, web sites, even personal conversations and unpublished manuscripts - cannot be reused without citing the source of your information.
Use footnotes or endnotes to give credit to a direct quotation.
Include a bibliography or list of works cited.
Follow guidelines from your instructor about citing your sources correctly. Choose one of the following standard citation formats:
APA - American Psychological Association (used in social sciences and some sciences)
CMS - Chicago Manual of Style (also called University of Chicago/Turabian) (used in other disciplines including humanities)
MLA - Modern Language Association (used in English and humanities)