@article{DE_1992_28_4_a7,
     author = {V. P. Nozdracheva},
     title = {Estimates for the periods of cycles generated by a structurally unstable separatrix loop},
     journal = {Differencialʹnye uravneni\^a},
     pages = {612--618},
     publisher = {mathdoc},
     volume = {28},
     number = {4},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1992_28_4_a7/}
}