1.		The future outlook for Portuguese travel agents / A. George Assaf, Carlos Pestana Barros, Luiz Pinto Machado Autor: Assaf, A. George Coautor: ; Barros, Carlos Pestana Machado, Luiz Pinto
2.		Covariates of repeat tourism: an endogenous switching Poisson model / Albert Assaf, Carlos Pestana Barros, Luiz Pinto Machado Autor: Assaf, Albert Coautor: ; Barros, Carlos Pestana Machado, Luiz Pinto