00313nam a2200109Ia 4500008004100000041000800041082001900049100002100068245007200089260003400161300000800195211209s1988    xx            000 0 und d  aeng  a005.43 N88 KEL  aKELLER, LAURIE S  aOPERATING SYSTEMS: COMMUNICATING WITH AND CONTROLLING THE COMPUTER   aNEW YORKbPRENTICE HALLc1988  a369