1. Babash, A.V., Baranova, E.K., Larin, D.A.: History of Information Protection in Russia, p. 736. Publisher Center EAOI, Moscow (2012). (in Russian)
2. Larin, D.A.: Cryptographic Service of Russia. Essays on History, p. 384. Helios-ARV, Moscow (2017). (in Russian)
3. Nikonov, V., Stolpakov, B.: Historical Evidence of the Beginning and Development of Russian Cryptography (XVI–XVII Centuries), p. 254. Media Group “Avangard,” Moscow (2016)
4. Tokareva, N.N.: On the history of cryptography in Russia. Prikl. Diskretn. Mat. 4(18), 82–107 (2012). (in Russian)
5. Babash, A.V., et al.: On the development of cryptography in the XIX century. In: Information Protection, No. 5 (2003) (in Russian)