@article{VNGU_2008_8_4_a2,
     author = {S. S. Goncharov and N. T. Kogabaev},
     title = {On $\Sigma^0_1${-Classification} of {Relations} on {Computable} {Structures}},
     journal = {Sibirskij \v{z}urnal \v{c}istoj i prikladnoj matematiki},
     pages = {23--32},
     year = {2008},
     volume = {8},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VNGU_2008_8_4_a2/}
}