00329nam a2200109Ia 4500008004100000040003800041100001400079245004900093260004500142300001700187653001500204211214s9999    xx            000 0 und d  cJayakar Knowledge Resource Centre  aRyan, T A 0aWork and effort: the psychology of prodution  bTHE RONALD PRESS COMPANYaNEW YORKc1947  aXII,323 P p.  aPSYCHOLOGY