@article{MZM_1989_45_6_a1,
     author = {L. D. Beklemishev},
     title = {Provability logic without {Craig's} interpolation property},
     journal = {Matemati\v{c}eskie zametki},
     pages = {12--22},
     publisher = {mathdoc},
     volume = {45},
     number = {6},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1989_45_6_a1/}
}