http://owl.english.purdue.edu/owl/section/2/8/
http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/Evaluate.html
http://www.writing.ku.edu/~writing/guides/evaluate.shtml
http://www.unc.edu/depts/wcweb/handouts/evidence.html
http://www.sass.uottawa.ca/writing/kit/stage2-research-evaluate.php