00297nam a2200109Ia 4500008004100000040002500041082001500066100002100081245002300102260005400125300000800179230627s9999    xx            000 0 und d  aNORSU-SiacNORSU-Sia  a512.56 C66  aCohm, Richard M. 0aDifference algebra  bRobert E. Kreiger Publishing Company, Inc. c1980  a355