@article{AL_1967_6_4_a12,
     author = {K. A. Zhevlakov},
     title = {Letter to the editor},
     journal = {Algebra i logika},
     pages = {113--117},
     publisher = {mathdoc},
     volume = {6},
     number = {4},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1967_6_4_a12/}
}