@article{DAN_1960_132_3_a11,
     author = {A. I. Perov},
     title = {Periodical, almost periodical and bounded solutions to differential equation $dx/dt=f(t,x)$},
     journal = {Doklady Akademii Nauk},
     pages = {531--534},
     publisher = {mathdoc},
     volume = {132},
     number = {3},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1960_132_3_a11/}
}