Gadzhev, Milen, and Danail Ivanov. “AGE-RELATED DIFFERENCES IN PHYSICAL AND TECHNICAL PERFORMANCE: A CROSS-SECTIONAL ANALYSIS OF ELITE BULGARIAN YOUTH FOOTBALL PLAYERS (U12–U14)”. KNOWLEDGE - International Journal 70, no. 3 (June 3, 2025): 305–309. Accessed August 25, 2026. https://ojs.ikm.mk/index.php/kij/article/view/7575.