@article{DE_1978_14_4_a8,
     author = {Yu. V. Churin},
     title = {An example of nonsimple vanishing of a periodic solution},
     journal = {Differencialʹnye uravneni\^a},
     pages = {652--660},
     publisher = {mathdoc},
     volume = {14},
     number = {4},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_4_a8/}
}