00451nam 2202671 45000010005000000030023000050050009000280080041000370820008000780720017000860200018001031000020001212600015001412500006001562450035001626500017001976500026002146500019002402671StarLibrary Marc Built20180420201711 ||||| |||||||||||amh  a621 aIntroduction a81-85095-87-6 aB. L. Brewester bEWP c1986 a3 aTele communications technology aIntroduction aThe telephone network aTrafifc theory