DIN EN 301914-2004 专用综合业务网.PINX和内联网络之间C参考点处QSIG的使用
Private Integrated Services Network (PISN) - Use of QSIG at the C reference point between a PINX and an interconnecting network (ISO/IEC 20161 (2001), modified) (Endorsement of the English version EN 301914 V1.1.1 (2004-01) as German standard)