@article{DE_1970_6_11_a0,
     author = {Yu. N. Bibikov},
     title = {The stability of periodic motions in transcendental critical cases},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1927--1945},
     publisher = {mathdoc},
     volume = {6},
     number = {11},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_11_a0/}
}