@article{ZVMMF_1968_8_1_a27,
     author = {M. R. Shura-Bura and M. I. Kabanov},
     title = {An empty word in a grammar of type~2},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {244--245},
     year = {1968},
     volume = {8},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1968_8_1_a27/}
}