001: 2671
003: Starlibrary PMS 4.5
005: 20180420
020: ^a81-85095-87-6
066: ^aB..T
072: ^aIntroduction
082: ^a621
100: ^aB. L. Brewester
240: ^aTele communications technology
245: ^aTele communications technology
260: ^c1986
650: ^aThe telephone network
650: ^aTrafifc theory