Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1962_143_2_a13, author = {T. F. Ivanov}, title = {Determination of periodic motions in conservative systems with one degree of freedom}, journal = {Doklady Akademii Nauk}, pages = {297--300}, publisher = {mathdoc}, volume = {143}, number = {2}, year = {1962}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1962_143_2_a13/} }
T. F. Ivanov. Determination of periodic motions in conservative systems with one degree of freedom. Doklady Akademii Nauk, Tome 143 (1962) no. 2, pp. 297-300. http://geodesic.mathdoc.fr/item/DAN_1962_143_2_a13/