1. C. O. Ruud, “X-Ray Analysis and Advances in Portable Field Instrumentation”, Journal of Metals, Vol. 31, No. 6, June 1979.
2. W. R. Junker and W. G. Clark, Jr., “Eddy Current Characterization of Applied and Residual Stresses”, ARPA/AFML Review of Progress in Quantitative NDE, San Diego, CA, August 1982.
3. Unpublished research work by G. E. Grotke and A. J. Bush, Westinghouse R&D Center.