Nitit, Fransiskus Saferius, Suwardi Suwardi, and Suriah Hanafi. 2026. “Application of Service Duel Approach to Improve High Secondary School Students’ Badminton Backhand Serve Accuracy ”. ETDC: Indonesian Journal of Research and Educational Review 6 (1):294-304. https://doi.org/10.51574/ijrer.v6i1.5179.