Mourtzios , C., E. . Kellis, and K. . Salonikidis. “Plantar Pressures Differences Between the Flat, Slice and Topspin Serves”. ITF Coaching & Sport Science Review, vol. 27, no. 78, Aug. 2019, pp. 32-34, doi:10.52383/itfcoaching.v27i78.92.