Valera, Luca, et al. “Gambling, Games of Skill and Human Ecology: A Pilot Study by a Multidimensional Analysis Approach”. Annali dell’Istituto Superiore Di Sanità, vol. 51, no. 4, Dec. 2015, pp. 358-65, https://annali.iss.it/index.php/anna/article/view/163.