1. K.-H. Rendigs: Mater. Sci. Forum, 1997, vol. 242, pp. 11–24.
2. S. Kallee and A. Mistry: Symp. on Friction Stir Welding, Thousands Oaks, CA, 1999.
3. O.T. Midling, J.S. Kvåle, and O. Dahl: Symp. on Friction Stir Welding, Thousands Oaks, CA, 1999.
4. W.M. Thomas, E.D. Nicholas, J.C. Needham, M.G. Church, P. Templesmith, and C.J. Dawes: International Patent, Application No. PCT/GB92, Patent Application No. 9,125,978.8, 1991.
5. E.D. Nicholas and W.M. Thomas: Int. J. Mater. Product Technol., 1998, vol. 13, pp. 45–54.