Parra López, E., Melchior, M. and Ramos, Ángel 2003. Analysis and impact of tour operators and travel agencies in tourist transport: new trends in the Canary Islands. PASOS Revista de Turismo y Patrimonio Cultural. 1, 2 (Jun. 2003), 217–229. DOI:https://doi.org/10.25145/j.pasos.2003.01.021.