@article{AL_1965_4_4_a2,
     author = {A. V. Gladkii},
     title = {The algorithmic undecidability of inherent ambiguity of},
     journal = {Algebra i logika},
     pages = {53--63},
     publisher = {mathdoc},
     volume = {4},
     number = {4},
     year = {1965},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1965_4_4_a2/}
}