M. Flayih و H. . Mahdi, "The effect of preventive exercises using the (isometric) method and aids to help develop the strength of the thigh muscles of the first-class referees of the Iraqi Premier League", jope, م 35, عدد 4, ص 1361–1343, 2023, doi: 10.37359/JOPE.V35(4)2023.1944.