http://www.socialpsychology.org/methods.htm#onlinetexts

http://www.socialpsychology.org/methods.htm

http://www.une.edu.au/WebStat/

http://udel.edu/~mcdonald/statpaired.html

http://www.stattutorials.com/EXCEL/EXCEL_TTEST1.html

http://en.wikipedia.org/wiki/Analysis_of_variance

http://www.bettersolutions.com/excel/EUN147/QT721212328.htm

http://mips.stanford.edu/public/classes/stats_data_analysis/lesson_8/234_8_d.html