https://owl.english.purdue.edu/owl/resource/560/01/

http://www.apastyle.org/

http://psychology.vanguard.edu/wp-content/uploads/2013/02/apastyleessentials.pdf

http://www.psych.uw.edu/writingcenter/writingguides/pdf/citations.pdf

https://owl.english.purdue.edu/owl/resource/747/01/

https://owl.english.purdue.edu/owl/resource/747/12/

https://owl.english.purdue.edu/media/jpeg/MLAPoster09.jpg

http://citationmachine.net/index2.php

http://www.bibme.org/

http://easybib.com/

https://owl.english.purdue.edu/owl/resource/583/03/

http://citesource.trincoll.edu/asa/asa.html