Eric Harris and Dylan Klebold

http://en.wikipedia.org/wiki/Eric_Harris_and_Dylan_Klebold,
http://www.dailymail.co.uk/news/article-2234542/Dylan-Klebold-Mother-Columbine-massacre-shooter-wanted-son-commit-suicide.html

http://rense.com/general14/columbinekillers.htm

http://911blogger.com/news/2006-11-17/columbine-911-connection

http://tech.mit.edu/V119/N22/littleton.22w.html

http://edition.cnn.com/2001/US/12/05/columbine.diary/

http://www.columbine-online.com/etc/columbine-faq.htm

http://www.nytimes.com/2004/04/24/opinion/the-columbine-killers.html

http://www.psychologytoday.com/blog/keeping-kids-safe/200905/columbine-bullying-and-the-mind-eric-harris

https://www.youtube.com/watch?v=3FCvYw2KFxM