DIN EN 300367:2000
综合业务数字网(ISDN).显式呼叫转接(ECT)补充业务.业务描述
Integrated Services Digital Network (ISDN) - Explicit Call Transfer (ECT) supplementary service - Service description (Endorsement of the English version EN 300367 V 1.2.1 (1998-10) as German standard)