@article{DAN_1987_295_5_a0,
     author = {K. Alymkulov},
     title = {On the appearance of a periodic solution from a loop of a},
     journal = {Doklady Akademii Nauk},
     pages = {1033--1036},
     publisher = {mathdoc},
     volume = {295},
     number = {5},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_295_5_a0/}
}