Ruaa Amer Ismaeel, Bushra Kadhum Abdul-ridha. The effect of critical speed exercises and mechanical ability to test the maximum speed of 400m runners under the age of 20 years. ms [Internet]. 2022 Dec. 30 [cited 2024 Dec. 19];21(4):0044-50. Available from: https://jcopew.uobaghdad.edu.iq/index.php/sport/article/view/1029