1. 1. Dorofeev, A.L., Kazamanov, Yu.G. (1980) Electromagnetic flaw detection. Moscow, Mashinostroenie [in Russian].
2. 2. Gerasimov, V.G., Pokrovsky, A.D., Sukhorukov, V.V. (1992) Non-destructive testing. In: 5 Books. Book 3: Electromagnetic testing. Moscow, Vysshaya Shkola [in Russian].
3. 3. Bilik, Yu.Z., Dorofeev, A.L. (1981) Electromagnetic flaw detectors of «Proba» type. Defektoskopiya, 6, 53-58 [in Russian].
4. 4. (1989) Eddy current flaw detector of TVD-A type. Technical description and operating instruction. Moscow, Ministry of Civil Aviation [in Russian].
5. 5. Arsh, E.I., Tverdostup, N.I., Khandetsky, V.S. (1981) Features of construction of self-oscillating meters on lambda-diodes. Izmeritelnaya Tekhnika, 1, 53-55 [in Russian].