@article{PDM_2021_3_a1,
     author = {O. V. Denisov},
     title = {Spectral probabilistic and statistical analysis {of~Markov} ciphers},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {12--31},
     publisher = {mathdoc},
     number = {3},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2021_3_a1/}
}