R&TTE Guide : Radio and telecommunications terminal equipment (R&TTE) / BSI - British Standard Institute
Interconnect costing / Peter Cartwright
Private postal operators in Europe : December 2000 / ed. Manner-Romberg Unternehmensberatung
Number portability 2001 : documentação da Conferência: Praga, 24- 26 de setembro de 2001 / org. IIR Telecoms & Technology