@article{DE_1989_25_8_a25,
     author = {M. I. Lapachugina and G. A. Leonov},
     title = {A frequency criterion for instability in the large of nonlinear dynamical systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1451--1453},
     publisher = {mathdoc},
     volume = {25},
     number = {8},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1989_25_8_a25/}
}