00285nam a2200097Ia 4500008004100000082001400041100001800055245008100073264002300154300001000177200527s9999||||xx |||||||||||||| ||und||  a152.4 ELM  aElms, Alan C. 0aRole Playing, Reward, and Attitude Change: An Enduring Problem in Psychology  bVan Nostrandc1969  a232p.