1. Silva, F., Borges, I., Costa, E., Pinto, A.S., Abreu, A.: Digital adaptation of the Portuguese museums educational service in a pandemic context—case study. In: de Mesquita A, Abreu A, Carvalho JV (eds) ICITED 2021. Smart innovation, systems and technologies (2021)
2. UNWTO: World tourism barometer 18(1) (2020)
3. UNWTO: Tourism and Intangible Cultural Heritage, 1ª UNWTO, Madrid (2012)
4. Richards, G. (ed.): Cultural Tourism in Europe. Cabi, Wallingford (re-issued in 2005 in electronic format by the Association for Tourism and Leisure Education (ATLAS) www.atlas.euro.org) (1996)
5. MacCannell, D.: The Tourist: A New Theory of the Leisure Class. Schoken Books, Nova Iorque (1976)