@article{DM_2001_13_4_a11,
     author = {S. A. Stepanov and M. Kh. Shalalfekh},
     title = {Letter to the editors},
     journal = {Diskretnaya Matematika},
     pages = {157},
     year = {2001},
     volume = {13},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2001_13_4_a11/}
}