@article{DM_1997_9_1_a8,
     author = {A. V. Babash},
     title = {Approximate models of permutation automata},
     journal = {Diskretnaya Matematika},
     pages = {103--122},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_1997_9_1_a8/}
}