1. J. Blitz, Electrical and Magnetic Methods of Nondestructive Testing, (Adam Hilger, Aristol, Philadelphia and New York, 1991), pp. 89–152.
2. Nondestructive Testing handbook, Vol. 5, Electromagnetic Testing, edited by S.S. Udpa, P. O. Moore, (American Society of Nondestructive Testing, Columbus, OH, 2004),. pp. 46–55, pp. 227-245, pp. 248-268.
3. M. C. Lugg, “Alternating Current Field Measurement,” in Electromagnetic Testing, edited by S. S. Udpa, P. O. Moore (American Society of Nondestructive Testing, Columbus, OH, 2004), pp. 257.
4. D. Jiles, Introduction to Magnetism and Magnetic Materials (Chapman & Hall, 1998), pp. 44.