1. Nondestructive testing: http://en.wikipedia.org/wiki/Nondestructive_testing .
2. F. J. Weinberg, Optics of Flame, Butterworth, London (1963).
3. W. Hauf and U. Grigull, Optical methods in heat transfer, Adv. in Heat Transfer, 6, 133–366 (1970).
4. K. S. Shifrin, Light Scattering in a Turbid Medium [in Russian], GITTL, Moscow (1951).
5. L. A. Chernov, Propagation of Waves in a Medium with Random Inhomogeneities [in Russian], Izd. AN SSSR, Moscow (1958).