Digelidis Ν., Kamtsios Σ., and Theodorakis Ι. “Physical Activity Levels, Exercise Attitudes, Self-Perceptions, Nutritional Behaviors and BMI Type of 12-Years Children”. Inquiries in Physical Education and Sport, vol. 5, no. 1, Apr. 2007, pp. 27-40, https://journals.lib.uth.gr/index.php/inquiries/article/view/1176.