1. K. Stahlkopf, G. R. Egan, and G. Dan, Recent advances in residual stress measurement, residual stresses in welded construction and their effects. Paper 43, International Conference, The Welding Institute, London, November 15?17 (1977).
2. B. P. Hildebrand and D. E. Nufford, Mapping residual stress field by ultrasonic tomography. Proceedings of the ARPA/AFML Review of Progress in quantitative NDE, Thousand Oaks, Calif. (May 1978).
3. J. D. Young and F. C. Lederman, Quantitative ultrasonic tomographic imaging. Proceedings of the ARPA/AFML Review of Progress in quantitative NDE, Thousand Oaks, Calif. (May 1978).
4. R. T. Smith, Note on tomography,Ultrasonic (July?September 1963).