Relative age effects in European soccer: their association with contextual factors, impact on youth national teams' performance, and presence at the senior level - Morganti, Gabriele; Kelly, Adam L.; Lascu, Alexandra; Brustio, Paolo R.; Padua, Elvira; Filetti, Cristoforo; Porta, Marco; Briotti, Gianluca; Ruscello, Bruno (Frontiers in Sports and Active Living, 2025)