1. La despesa turı́stica;Aguiló,1997
2. Recreational demand by tourists for saltwater beach days;Bell;J. Environ. Econom. Management,1990
3. M. Blázquez, Els usos recreatius turı́stics dels Espais Naturals Protegits. L'abast del lleure al medi natural de Mallorca, Doctoral thesis, University of the Balearic Islands, 1996.
4. Measuring the Benefits of Water Quality Improvements Using Recreational Demand Models;Bockstael,1989
5. Recreation;Bockstael,1992