DIN ETS 300570:1995 European digital cellular telecommunications system (phase 2) - Advice of Charge (AoC) supplementary services, stage 3; English version ETS 300570:1995
1995DIN ETS 300570:1995 European digital cellular telecommunications system (phase 2) - Advice of Charge (AoC) supplementary services, stage 3; English version ETS 300570:1995