1[1]GSM 0339(Version 6.0.0):European digital cellular telecommunications syste m(Phase 2+);Interface protocols for the connection of Short Message Service Cent res(SMSCs)to Short Message Entities(SMEs)[S].
2[2]GSM 0340(Version 6.0.0):European digital cellular telecommunications syste m(Phase 2);Technical realization of the Short Message Service Point to Point[S ].
3[3]Short Message Pere to Pere Protocol Specification v3.4（document version:- 12-oct-1999 issue 1.2）[S].
