@article{SM_1987_56_2_a2,
     author = {V. V. Rybakov},
     title = {Bases of admissible rules of the modal system {Grz} and of intuitionistic logic},
     journal = {Sbornik. Mathematics},
     pages = {311--331},
     publisher = {mathdoc},
     volume = {56},
     number = {2},
     year = {1987},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1987_56_2_a2/}
}