Abduljabbar, I., A. Sabah, and I. Salih Mahmo. “The Effect of Using Balls of Different Weights and Sizes on Passing and Shooting Accuracy of Juniors Football Players”. Al-Rafidain Journal For Sport Sciences, vol. 17, no. 57, Dec. 2011, pp. 183-99, doi:10.33899/rajsport.2011.163150.