@article{DE_1991_27_8_a1,
     author = {A. N. Belyaeva and I. G. Egorov},
     title = {On the {A{\v\i}zerman} problem for a second-order system},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1297--1303},
     publisher = {mathdoc},
     volume = {27},
     number = {8},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_8_a1/}
}