00269nam a2200109Ia 4500008004100000041000800041100003200049245004100081260001200122365000600134999001900140231011s9999    xx            000 0 und d  aeng  aChurchman C.W. Ackoff. R.L.  aIntroduction to Operations Rescarch.  bOTHER -  b9  c883251d883251