1. Brunekreeft, G. (1998). Peak-load pricing, perfect competition and price discrimination. Discussion paper, No. 53, University of Freiburg, October.
2. Büchner, W., Ehmer, J., Geppert, M., Kerkhoff, B., Piepenbrock, H., Schütz, R., & Schuster, F. (Eds.). (1997). Beck'scher TKG-Kommentar. C. H. Beck'sche Verlagsbuchhandlung.
3. Connect-online. (1999). Telekom-Konkurrenten stoßen an Wachstumsgrenzen. Connect-online, 23 March.
4. Dohmen, F. (1998). Kaum noch Luft. Der Spiegel, No. 53/1998.
5. Joint supply, the Taussig-Pigou controversy and the competitive provision of public goods;Ekelund;Journal of Law and Economics,1973