@article{IIMI_2018_51_a4,
     author = {N. N. Petrov and N. V. Petrova},
     title = {On the problem of diversifying the ruble},
     journal = {Izvestiya Instituta Matematiki i Informatiki Udmurtskogo Gosudarstvennogo Universiteta},
     pages = {123--135},
     publisher = {mathdoc},
     volume = {51},
     year = {2018},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IIMI_2018_51_a4/}
}