Calling Circles: Network Competition with Nonuniform Calling Patterns
Steffen Hoernig, Roman Inderst, Tommaso Valletti
Rand Journal of Economics, vol. 45, 2014, p. 155-175.

Mixing Goods with Two-Part Tariffs
Steffen Hoernig, Tommaso Valletti
European Economic Review, vol. 51, 2007, p. 1733-1750.

Universal Service and Entry: The Role of Uniform Pricing and Coverage Constraints
Tommaso Valletti, Steffen Hoernig, Pedro Pita Barros
Journal of Regulatory Economics, vol. 21, 2002, p. 169-190.