@article{TM_1973_133_a19,
     author = {B. A. Trakhtenbrot},
     title = {Frequency computations},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {221--232},
     year = {1973},
     volume = {133},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1973_133_a19/}
}