Green book 17th plenary assembly; v.4
Comite Consultatif International Telephonique (CCIF).
Green book 17th plenary assembly; v.4 - Switzerland C.C.I.F 1956
621.38506 / N55.4 "R"
Green book 17th plenary assembly; v.4 - Switzerland C.C.I.F 1956
621.38506 / N55.4 "R"