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@article{DE_1967_3_7_a2, author = {L. A. Cherkas}, title = {Stability of a singular cycle in the critical case}, journal = {Differencialʹnye uravneni\^a}, pages = {1060--1069}, publisher = {mathdoc}, volume = {3}, number = {7}, year = {1967}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1967_3_7_a2/} }
L. A. Cherkas. Stability of a singular cycle in the critical case. Differencialʹnye uravneniâ, Tome 3 (1967) no. 7, pp. 1060-1069. http://geodesic.mathdoc.fr/item/DE_1967_3_7_a2/