00475nam 2202457 45000010005000000030023000050050009000280080041000370820008000780720029000860200018001151000016001332600024001492500006001732450066001796500029002456500021002742457StarLibrary Marc Built20180420201711 ||||| |||||||||||amh  a621 adigital telphone systems a0-07-001069-2 asyeedr. ali bMCGRAW. HILL c1998 a2 aDigital Switching Systems bsystems reliability and analysis adigital telphone systems asystems analysis