Papaioannou Α., Bebetsos Ε., Kafetzi Σ., and Sagovitch Α. “Preliminary Investigation of a Questionnaire, Based On the Model of Stages and Processes of Change towards Exercise - Physical Activity”. Inquiries in Physical Education and Sport, vol. 4, no. 1, Apr. 2005, pp. 78-86, https://journals.lib.uth.gr/index.php/inquiries/article/view/1123.