@article{DAN_1961_136_1_a12,
     author = {Ya. I. Sekerzh-Zen'kovich},
     title = {On the theory of free finite oscillations of a surface separating two unbounded heavy liquids of different densities},
     journal = {Doklady Akademii Nauk},
     pages = {51--54},
     publisher = {mathdoc},
     volume = {136},
     number = {1},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_136_1_a12/}
}