1. H. L. Libby, Introduction to Electromagnetic Non‐destructive Test Methods (Wiley, New York, 1971).
2. W. Hunt, Jr. and R. Stein, Static Electromagnetic Devices (Allyn and Bacon, Boston, 1963), Ch. 3.
3. L. H. Cook, Jr., in Symposium on Non‐destructive Tests in the Field of Nuclear Energy, ASTM Special Technical Pub. ♯223 (American Society for Testing and Materials, Philadelphia, 1958), p. 225;
4. W. H. Tait, J. Electrodepositor’s Tech. Soc. 14, 108 (1938);
5. R. S. Bennett, J. Sci. Instrum. 26, 208 (1949); JSINAY0950-7671