Marenzi, Ivana, Elena Demidova, Wolfgang Nejdl, Daniel Olmedilla, and Sergej Zerr. “Social Software for Lifelong Competence Development: Challenges and Infrastructure”. International Journal of Emerging Technologies in Learning (iJET) 3 (July 5, 2008): pp. 18–23. Accessed August 13, 2022. https://online-journals.org/index.php/i-jet/article/view/545.