@article{DAN_1989_306_6_a12,
     author = {K. F. Chernykh},
     title = {On the necessity of taking geometric nonlinearity into account in},
     journal = {Doklady Akademii Nauk},
     pages = {1336--1338},
     publisher = {mathdoc},
     volume = {306},
     number = {6},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_306_6_a12/}
}