Yimer, Mohammednasir, Aemero Asmamaw, and Zerihun Birhanu. “Comparación Del Estado físico De Jugadores De Fútbol juveniles’ etíopes Entrenados Por Entrenadores De Sistemas De Aprendizaje De Entrenadores Formales E Informales (Comparison of Physical Fitness Status of Ethiopian Youth Football Players Trained by Coaches from Formal and Informal Coach Learning Systems)”. Retos 60 (November 1, 2024): 377–382. Accessed June 13, 2026. https://revistaretos.org/index.php/retos/article/view/107559.