@article{DAN_1958_121_1_a7,
     author = {T. M. Karaseva},
     title = {On an {\textquotedblleft}exact estimate{\textquotedblright} of the multipliers of second order differential equations with periodical coefficients},
     journal = {Doklady Akademii Nauk},
     pages = {34--36},
     year = {1958},
     volume = {121},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1958_121_1_a7/}
}