Martínez-Gallego, R., Guzmán, J. F., James, N., Ramón-Llin, J., Crespo, M., & Vuckovic, G. (2013). The relationship between the incidence of winners/errors and the time spent in different areas of the court in elite tennis. Journal of Human Sport and Exercise, 8(3proc), S601-S607. https://doi.org/10.4100/jhse.2013.8.Proc3.05