Öztürk, B., B. Büyüktaş, İbrahim Bahçivan, M. Balikçi, and L. Sangün. “Concurrent Validity of the Athla Velocity Application for Measuring Tennis Service Ball Velocity”. 2023. Journal of Human Sport and Exercise, vol. 18, no. 3, July 2023, pp. 701-8, doi:10.14198/jhse.2023.183.16.