@article{DE_1991_27_6_a21,
     author = {V. V. Veremenyuk},
     title = {The existence of the rotation number of the equation $\dot x=\lambda (t,x)$ with a right-hand side that is periodic in $x$ and almost periodic in $t$},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1073--1076},
     publisher = {mathdoc},
     volume = {27},
     number = {6},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_6_a21/}
}