[1] Lang, S. (1968) Algebra (in Russian). Moscow, Mir.
[2] Sachkow, W.N. (1977) Combinatric Methods of Descret Mathematics (in Russian). Nauka, Moscow.
[3] Leontiev, V.K., Movsisyan, G.L. and Margaryan, J.G. (2006) Perfect Codes in Additive Channels. Reports of RAS, 411, 306-309 (in Russian).
[4] Leontiev, V.K., Movsisyan, G.L. and Margaryan, J.G. (2008) On Perfect Codes in Additive Channels. Problems of Information Transmission, 44, 12-19.
[5] Leontiev, V.K., Movsisyan, G.L. and Margaryan, J.G. (2010) Correction of Errors in an Additive Channel. Vol. 2, Westnik RAU, 12-25 (in Armenian).