@article{DAN_1970_194_5_a8,
     author = {V. S. Proskurov},
     title = {A theorem on the coding of expressions in arbitrary languages},
     journal = {Doklady Akademii Nauk},
     pages = {1021--1024},
     publisher = {mathdoc},
     volume = {194},
     number = {5},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1970_194_5_a8/}
}