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@article{DE_1991_27_8_a6, author = {A. A. Levakov}, title = {Stability of $\Pi$-systems}, journal = {Differencialʹnye uravneni\^a}, pages = {1334--1344}, publisher = {mathdoc}, volume = {27}, number = {8}, year = {1991}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1991_27_8_a6/} }
A. A. Levakov. Stability of $\Pi$-systems. Differencialʹnye uravneniâ, Tome 27 (1991) no. 8, pp. 1334-1344. http://geodesic.mathdoc.fr/item/DE_1991_27_8_a6/