Marc, R. L., Emeka, T. O., David, C. B., & Zisan, K. C. (2015). ACHIEVEMENT GOALS AND INTENSIVITY OF PHYSICAL ACTIVITY DURING FREE PLAY IN CHILDREN: THE MODERATING ROLE OF PERCEIVED SPORT CONFIDENCE. Pedagogics, Psychology, Medical-Biological Problems of Physical Training and Sports, 19(11), 72–77. https://doi.org/10.15561/18189172.2015.1111