A Third Sector in the Core-Periphery Model: Non-tradable Goods
Vasco Leite, Sofia Castro, João Correia da Silva
Annals Of Regional Science, vol. 50, 2013, p. 71-108.

The Core Periphery Model with Asymmetric Inter-regional and Intra-regional Trade Costs
Vasco Leite, Sofia Castro, João Correia da Silva
Portuguese Economic Journal, vol. 8, 2009, p. 37-44.