00395nam a2200181Ia 4500003000400000005001700004006001900021007000300040008004100043024001100084037001200095040002000107041001300127082001400140100001900154245003100173260000900204OSt20220928151545.0a|||||r|||| 00| 0 ta220927b        |||||||| |||| 00| 0 eng d  a126891  cTextual  aSDCLcSDCLbeng  2engaeng  aD65,4, M6  aLangley Graham 0aTelecommunications primer.  c1986