@article{VNGU_2009_9_2_a5,
     author = {S. I. Mardaev},
     title = {Fixed {Points} of {Formulas} with {Double} {Modalities}},
     journal = {Sibirskij \v{z}urnal \v{c}istoj i prikladnoj matematiki},
     pages = {55--58},
     publisher = {mathdoc},
     volume = {9},
     number = {2},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VNGU_2009_9_2_a5/}
}