Shakir, H., A. . Khazal Jabbar, و W. . Louis William. "Effect of Interval Training With Two Methods Gradual and Intermittent in Development of Some Special Physical Variables and Achievement of Running 400 M for Juniors". مجلة دراسات وبحوث التربية الرياضية, م 36, عدد 4, يوليو، 2026, doi:10.55998/jsrse.v36i4.1450.