@article{AL_1992_31_1_a5,
     author = {A. V. Chagrov},
     title = {A decidable modal logic for which the admissibility of},
     journal = {Algebra i logika},
     pages = {83--93},
     publisher = {mathdoc},
     volume = {31},
     number = {1},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1992_31_1_a5/}
}