S. A. Amin, M. Y. Hanna, and A. F. Mohamed, “Experimental Study the Effect of Tool Design on the Mechanical Properties of Bobbin Friction Stir Welded 6061-T6 Aluminum Alloy”, alkej, vol. 14, no. 3, pp. 1–11, Sep. 2018, doi: 10.22153/kej.2018.01.003.