@article{DAN_1969_185_1_a14,
     author = {A. A. Letichevskii},
     title = {Functional equivalence of automata with a final state},
     journal = {Doklady Akademii Nauk},
     pages = {58--60},
     publisher = {mathdoc},
     volume = {185},
     number = {1},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_185_1_a14/}
}