@article{DE_1993_29_6_a17,
     author = {I. M. Burkin},
     title = {A frequency criterion for the orbital stability of limit cycles of the second kind},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1061--1063},
     publisher = {mathdoc},
     volume = {29},
     number = {6},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1993_29_6_a17/}
}