Noumba Um, P. (2004). A model for calculating interconnection costs in telecommunications. World Bank : PPIAF.
Citace podle Chicago (17th ed.)Noumba Um, Paul. A Model for Calculating Interconnection Costs in Telecommunications. Washington, D.C.: World Bank : PPIAF, 2004.
Citace podle MLA (9th ed.)Noumba Um, Paul. A Model for Calculating Interconnection Costs in Telecommunications. World Bank : PPIAF, 2004.