Mathisen, Gunnar E., Rein M. Jensen, in Svein A. Pettersen. 2016. „Aerobic Games and Playful Exercises in 9-Year-Old Boys: Intensity and Fitness Effects“. Revija Za Elementarno izobraževanje 9 (1/2): 57-64. https://old.journals.um.si/index.php/education/article/view/374.