1. Boujemaa, F. etal: Introduction of Distributed Computing Middleware in Intelligent Networks, White Paper, OMG telecom/97–09-01, 1997,
ftp://ftp.omg.org/pub/docs/telecom/97-09-01.pdf
2. ETSI DTS/SMG-012205U Universal Mobile Telecommunications System (UMTS); Services and Service Capabilities; (UMTS 22.05 version 2.0.0)
3. ETSI DTS/SMG-012270U Universal Mobile Telecommunications System (UMTS); service aspects; Virtual Home Environment (VHE); (UMTS 22.70 version 2.0.0)
4. ETSI DTS/SMG-012271U Universal Mobile Telecommunications System (UMTS); Service aspects; Automatic Establishment of Roaming Relationships; (UMTS 22.71 version 2.0.0)
5. Fowler, M. etal.: UML Distilled Addison-Wesley, 1997