Gravetter, Frederick J. Statistics for the behavioral sciences / Frederick J Gravetter, Larry B. Wallnau. - 9th ed. - Belmont, CA : Wadsworth Cengage Learning, c2013. - xxi, 767 p. : ISBN: 9781111830991 (hbk.) 1111830991 (hbk.) 9781111835767 (looseleaf) 1111835764 (looseleaf) Subjects--Topical Terms: PsychologyEducational statistics.