Al-jarrah, J. A., A. Ibrahim, and S. Sawlaha. “Effect of Applied Pressure on the Mechanical Properties of 6061 Aluminum Alloy Welded Joints Prepared by Friction Stir Welding”. Engineering, Technology & Applied Science Research, vol. 7, no. 3, June 2017, pp. 1619-22, doi:10.48084/etasr.1124.