@article{PDM_2008_2_a9,
     author = {A. M. Kukartsev and A. M. Popov and V. S. Shestakov},
     title = {About the direct operational analysis of symmetric ciphers},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {45--49},
     publisher = {mathdoc},
     number = {2},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2008_2_a9/}
}