001: 989
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 Communicetions and Networks
245: ^aComputer Communicetions and Networks
260: ^c1988
650: ^adata communication concepts and alternatives
650: ^amodems and multiplexers