References
Cartz, Louis, Nondestructive Testing, ASM Intl, Metals Park, OH, 1995, ISBN: 0871705176
Introduction to Capillary Testing Theory, Borovikov, A.S. (Ed.), Minsk, Nauka i Tekhnika Publishing, 1988
Liquid Penetrant Testing, Nondestructive Testing Handbook, Volume 2, Tracy, Noel (Tech. Ed.), Moore, Patrick (Ed.) American Society for Nondestructive Testing, Columbus, OH, 1999, ISBN 1-57117-028-6