Wanick, Vanissa, and Hong Bui. “Gamification in Management: A Systematic Review and Research Directions”. International Journal of Serious Games 6, no. 2 (June 24, 2019): 57 - 74. Accessed September 15, 2019. http://journal.seriousgamessociety.org/index.php/IJSG/article/view/282.