@article{DE_2000_36_10_a1,
     author = {I. T. Kiguradze and T. Kusano},
     title = {Conditions for the existence and uniqueness of periodic solutions of nonautonomous differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1301--1306},
     publisher = {mathdoc},
     volume = {36},
     number = {10},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2000_36_10_a1/}
}