Aman S. Khasawneh, Ahmed A. Akor, Ahemd M. Adel, and Waleed Iyadat. “The Influence of Feedback on Performance of Serving and Reception Skills in Volleyball”. The Shield - Research Journal of Physical Education &Amp; Sports Science, vol. 3, Dec. 2008, doi:10.57038/theshield.v3i0.2717.