Kalapoda Ε., Michalopoulou Μ., Betichavas Ά., Ageloussis Ν. and Taxildaris Κ. (2003) “Discovery Learning and Modeling in Teaching Tennis Skills”, Inquiries in Physical Education and Sport, 1(3), pp. 228–237. doi: 10.26253/heal.uth.ojs.ispe.2003.1017.