Half-squat or jump squat training under optimum power load conditions to counteract power and speed decrements in Brazilian elite soccer players during the preseason - Loturco, I.; Pereira, L. A.; Kobal, R.; Zanetti, V.; Gil, S.; Kitamura, K.; Cavinato Cal Abad, C.; Nakamura, F. Y. (Journal of Sports Sciences, 2015)