WIDIYANTO, Widiyanto et al. Article RETRACTED due to manipulation by the authors Los diferentes resultados en lsa habilidades de servicio de los tenistas jóvenes evaluadas según el género y la edad (The Differences Result in Serve Skill of Junior Tennis Players Assessed Based on Gender and Age): Article RETRACTED due to manipulation by the authors. Retos, [S. l.], v. 54, p. 272–278, 2024. DOI: 10.47197/retos.v54.102757. Disponível em: https://www.revistaretos.org/index.php/retos/article/view/102757. Acesso em: 10 jun. 2026.