DIN ETS 300517:2001-04 Digital cellular telecommunications system (Phase 2) - Multi Party (MPTY) supplementary services - Stage 1 (Endorsement of the English version ETS 300517:1996-05 as German standard) / Note: Endorsement notice
2001DIN ETS 300517:2001-04 Digital cellular telecommunications system (Phase 2) - Multi Party (MPTY) supplementary services - Stage 1 (Endorsement of the English version ETS 300517:1996-05 as German standard) / Note: Endorsement notice
2001DIN ETS 300517:2001 Digital cellular telecommunications system (Phase 2) - Multi Party (MPTY) supplementary services - Stage 1 (Endorsement of the English version ETS 300517:1996-05 as German standard)