@article{DAN_1962_145_3_a12,
     author = {An. M. Leontovich},
     title = {The existence of unbounded oscillating trajectories in a problem of billiards},
     journal = {Doklady Akademii Nauk},
     pages = {523--526},
     publisher = {mathdoc},
     volume = {145},
     number = {3},
     year = {1962},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1962_145_3_a12/}
}