DIN ETS 300568:1995 European digital cellular telecommunications system (phase 2) - MultiParty (MPTY) supplementary services, stage 3; English version ETS 300568:1995
1995DIN ETS 300568:1995 European digital cellular telecommunications system (phase 2) - MultiParty (MPTY) supplementary services, stage 3; English version ETS 300568:1995