@article{RM_1985_40_1_a22,
     author = {I. A. Rudakov},
     title = {A problem on free periodic vibrations of a~string with non-monotone non-linearity},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {237--238},
     publisher = {mathdoc},
     volume = {40},
     number = {1},
     year = {1985},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1985_40_1_a22/}
}