001: 18408
003: Starlibrary PMS 4.5
005: 20180430
020: ^a81-85336-33-4
066: ^aJo.C
072: ^acommunications media
082: ^a004.6
100: ^aJohn Freer
240: ^aCOMPUTER COMMUNICATION AND NETWORKS
245: ^aCOMPUTER COMMUNICATION AND NETWORKS
260: ^c1990
650: ^adata communication concepts and alternatives
650: ^amodems and multiplexers