Mangione, Giuseppina Rita, Francesco Orciuoli, Anna Pierri, and Saverio Salerno. “Competence Management in E-Learning Systems: A Possible Approach”. Journal of e-Learning and Knowledge Society 5, no. 3 (December 21, 2009). Accessed August 12, 2020. https://www.je-lks.org/ojs/index.php/Je-LKS_EN/article/view/354.