Suci Nanda Sari and Juana Wangsa Putri 2022. The Effect of Feedback and Motivation on Service Ability in Junior Tennis Athletes in West Sumatera. JIPES - JOURNAL OF INDONESIAN PHYSICAL EDUCATION AND SPORT. 8, 1 (Aug. 2022), 10–14. DOI:https://doi.org/10.21009/JIPES.081.02.