@article{IVM_1982_9_a11,
     author = {F. M. Ablayev},
     title = {Metrization criterion for regularity of languages representable in countable automata},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {67--69},
     publisher = {mathdoc},
     number = {9},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1982_9_a11/}
}