@article{AL_1963_2_3_a0,
     author = {A. V. Gladkii},
     title = {On the recognition of replaceability in recursive languages},
     journal = {Algebra i logika},
     pages = {5--22},
     publisher = {mathdoc},
     volume = {2},
     number = {3},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1963_2_3_a0/}
}