http://scienceline.org/2006/10/ask-driscoll-tears/
http://www.healthblurbs.com/tears-tear-glands-dry-eyes-excessive-tearing/
http://www.nlm.nih.gov/medlineplus/tears.html
http://www.webmd.com/balance/features/why-we-cry-the-truth-about-tearing-up
http://www.sciencedaily.com/releases/2009/08/090824141045.htm
http://www.healthblurbs.com/tears-tear-glands-dry-eyes-excessive-tearing/
http://www.nlm.nih.gov/medlineplus/tears.html
http://www.webmd.com/balance/features/why-we-cry-the-truth-about-tearing-up
http://www.sciencedaily.com/releases/2009/08/090824141045.htm