1. H.L. Libby:Introduction to Electromagnetic Nondestructive Test Methods (Wiley Interscience, New York 1971). [Gives numerous references]
2. C.H. Larsen, R.A. Egen, R.D. Jones, H.A. Cross: Report to the U.S. Bureau of Mines on Contract No. H0101741, June (1971)
3. J.G. Lang: The Canadian Mining and Metallurgical (CIM) Bulletin. 415 (1969)
4. E.R. Hoskins: Report to the U.S. Bureau of Mines of Contract No. H0346193 (South Dakota School of Mines & Technology) July (1975)
5. D.A. Hill, J.R. Wait: J. Appl. Phys.48, 4893 (1977)