Castellano, Julen, David Casamichana, and Oier Agirrezabalaga. “¿Es Posible Proponer Una Estrategia De periodización Diferente De La U Invertida En Pretemporada? Una comparación Entre Dos Equipos De Fútbol Profesional (Is It Possible to Propose a Periodization Strategy Different from the Inverted U in Preseason? A Comparison Between Two Professional Football Teams)”. Retos 56 (July 1, 2024): 917–924. Accessed December 18, 2025. http://207.180.252.49/index.php/retos/article/view/103792.