Noumba Um, P. (2004). A model for calculating interconnection costs in telecommunications. World Bank : PPIAF.
Chicago-referens (17:e uppl.)Noumba Um, Paul. A Model for Calculating Interconnection Costs in Telecommunications. Washington, D.C.: World Bank : PPIAF, 2004.
MLA-referens (9:e uppl.)Noumba Um, Paul. A Model for Calculating Interconnection Costs in Telecommunications. World Bank : PPIAF, 2004.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.