Widiyanto, W. et al. 2024. 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. 54, (May 2024), 272–278. DOI:https://doi.org/10.47197/retos.v54.102757.