Gadzhev M, Ivanov D. AGE-RELATED DIFFERENCES IN PHYSICAL AND TECHNICAL PERFORMANCE: A CROSS-SECTIONAL ANALYSIS OF ELITE BULGARIAN YOUTH FOOTBALL PLAYERS (U12–U14). kij [Internet]. 2025 Jun. 3 [cited 2026 Aug. 27];70(3):305-9. Available from: https://ojs.ikm.mk/index.php/kij/article/view/7575