00430nam a2200157Ia 450000500170000000800410001702000180005804100080007608200160008410000200010024500310012026000410015130000100019244000260020265000440022820191111130253.0190710s9999    xx            000 0 und d  a0-416-82790-X  aeng  a154.4 W1541  aWalker, Stephen 0aLearning and reinforcement  aLondonb: Methuen and Company,c1975  a144p.  aEssential psychology   aPsychologya| Learninga| Reinforcement