RATSIMBANIERANA, H.; SBAI, S. .; STENGER, A. . Moroccan tourist portfolio efficiency with the mean-variance approach. European Journal of Tourism Research, [S. l.], v. 6, n. 2, p. 122–131, 2013. DOI: 10.54055/ejtr.v6i2.126. Disponível em: https://www.ejtr.vumk.eu/index.php/about/article/view/126. Acesso em: 12 nov. 2026.