61. | Specifications of signalling systems Nos. 4 and 5 : recommendations Q.120 - Q.180 / International Telecommunication UnionData Publicação: 1989 Tema: Vária | ![]() | |
62. | Interworking of signalling systems : recommendations Q.601-Q.699 / International Telecommunication UnionData Publicação: 1989 Tema: Vária | ![]() | |
63. | Telephone transmission quality : series P recommendations / International Telecommunication UnionData Publicação: 1989 Tema: Vária | ![]() | |
64. | Data communication over the telephone network : series V recommendations / International Telecommunication UnionData Publicação: 1989 Tema: Vária | ![]() | |
65. | Opinions and resolutions recommendations on the organization and working procedures of CCITT (series A) / International Telecommunication UnionData Publicação: 1989 Tema: Vária | ![]() |