Lopes, Érika, R. Marques, and A. Cavenaghi. “Hospitality, Social Ties and Emotional Vulnerability: A Systematic Literature Review ”. Journal of Hospitality, Vol. 2, no. 3-4, June 2020, pp. 60-71, http://htmjournals.com/jh/index.php/jh/article/view/24.