@article{DM_1991_3_1_a0,
     author = {V. I. Levenshtein},
     title = {Perfect codes in the metric of deletions and insertions},
     journal = {Diskretnaya Matematika},
     pages = {3--20},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_1991_3_1_a0/}
}