Miranda Cordeiro, B. F., L. R. Simões Alves, and P. M. Carvalho Tomás. “Ecotourism in Portugal: Characterization of the Offer Focused on Agents of Touristic Animation”. PASOS Revista De Turismo Y Patrimonio Cultural, vol. 15, no. 3, June 2017, pp. 731-40, doi:10.25145/j.pasos.2017.15.048.