Alhofy, Mahmoud1 Yousef, Abdel Halim2 Torky, Mahmoud3 Shehab, Ahmed4 .. "Effect of protective training to reduce some of the knee joint injuries on the artificial grass playground on the junior soccer players". Journal of Theories and Applications of Physical Education Sport Sciences, 5, 1, 2021, 1-20. doi: 10.21608/jat.2021.225676