1ESTI. GSM 03 40 Digital cellular telecommunication system (Phase 2-k ): Technical realization of the Short Message Service (SMS) Point to Point (PP) [S], 1998.
2ESTI. GSM 07 05 Digital cellular telecommunication system (Phase 2+) Use of Data Terminal Equipment- Data Circuit terminating Equipment (DTE - DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS) [S] ,1999.
3Shiflett C. HTTP Developer's Handbook[M]. USA: Sams, 2003.