L. Carvalho, Fátima, and Sílvia C. Fernandes. “COVID-19 Impact on Tourism: The System Thinking Approach Applied to the Case of Portugal”. Journal of Tourism, Sustainability and Well-being 10, no. 2 (June 30, 2022): 75–87. Accessed October 27, 2025. https://journals.cinturs.pt/jtsw/article/view/307.