@article{SM_1977_31_2_a8,
     author = {S. K. Sobolev},
     title = {On finite approximability of superintuitionistic logics},
     journal = {Sbornik. Mathematics},
     pages = {257--268},
     publisher = {mathdoc},
     volume = {31},
     number = {2},
     year = {1977},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1977_31_2_a8/}
}