Kalapoda Ευπραξία, Michalopoulou Μαρία, Betichavas Άγγελος, Ageloussis Νίκος, and Taxildaris Κυριάκος. 2003. “Discovery Learning and Modeling in Teaching Tennis Skills”. Inquiries in Physical Education and Sport 1 (3):228-37. https://journals.lib.uth.gr/index.php/inquiries/article/view/1017.