“The Gymnaestrada in Zagreb ( July 10th-14th) and the Congress for Physical education (July 14th-17th, 1957)”, FIEP-Bulletin, vol. 57, no. 5-6, Aug. 2015, Accessed: Apr. 25, 2025. [Online]. Available: https://ojs.fiepbulletin.net/fiepbulletin/article/view/5407