@article{SM_1969_8_1_a3,
     author = {V. S. Ryaben'kii},
     title = {On~systems of difference equations on~polyhedra},
     journal = {Sbornik. Mathematics},
     pages = {73--85},
     publisher = {mathdoc},
     volume = {8},
     number = {1},
     year = {1969},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1969_8_1_a3/}
}