Landau, S., & Everitt, B. S. (2004). A handbook of statistical analyses using SPSS. Boca Raton, FL: CRC.
Verzani, J. (2005). Using R for introductory Statistics. Boca Raton, FL: CRC.
G*Power 3 is a power analysis program. Free
IBM SPSS Statistics is an integrated family of graphical-based data analysis products. $