Sugiarto , Aas, Supriyanto Supriyanto, and Mesterjon Mesterjon. 2021. “The Relationship Of Waist Flexibility Towards Smash Skills In Volley Ball Extracurricular Athletes In Sma N 13 Bengkulu Utara”. Sinar Sport Journal 1 (1):1-3. https://doi.org/10.53697/ssj.v1i1.66.