@article{RM_1972_27_4_a12,
     author = {N. A. Bobylev},
     title = {The method of mechanical quadratures in the problem of periodic solutions},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {27},
     number = {4},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1972_27_4_a12/}
}