Groffik, D., Frömel, K., Witek-Chabińska, M., Szyja, R., Žatka, R. and Urbański, B. 2019. Daily and school physical activity of 16 year-old girls and boys. Health Promotion & Physical Activity. 4, 3 (Jan. 2019), 12–19. DOI:https://doi.org/10.5604/01.3001.0012.8669.