@article{DM_2014_26_2_a5,
     author = {A. A. Petyushko},
     title = {On cardinality of bigram languages},
     journal = {Diskretnaya Matematika},
     pages = {71--82},
     publisher = {mathdoc},
     volume = {26},
     number = {2},
     year = {2014},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2014_26_2_a5/}
}