Koskeris, Andreas, and Thanassis Karalis. “Non – Formal Education Activities For The Enhancement Of Knowledge And Skills: Investigation Of Non-Explicit Motives For Participation”. European Scientific Journal, ESJ 12, no. 19 (July 29, 2016): 32. Accessed April 26, 2024. https://eujournal.org/index.php/esj/article/view/7717.