@article{DAN_1967_175_1_a0,
     author = {Yu. G. Borisovich and V. F. Subbotin},
     title = {The displacement operator on the trajectories of equations of evolution, and periodic solutions},
     journal = {Doklady Akademii Nauk},
     pages = {9--12},
     publisher = {mathdoc},
     volume = {175},
     number = {1},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1967_175_1_a0/}
}