Dave Ramsey's envelope system

http://www.daveramsey.com/blog/envelope-system-explained

Stats help

http://web.stanford.edu/~kcobb/hrp258/lecture7_na.ppt

http://archive.bio.ed.ac.uk/jdeacon/statistics/tress4.html

http://www.sfu.ca/~ber1/iat802/pdfs/When%2520to%2520use%2520what%2520test.pdf