[1]
P. Born, H.-P. Born, R. Bornemann, A. Jakubec, and T. Vogt, “10 years Tennis Play and Stay: A review on communicating and teaching tennis from (pre)school to advanced ages in Germany”, ITF Co. & Sp. Sc. Rev., vol. 25, no. 72, pp. 4–7, Aug. 2017.