@article{VMUMM_2012_5_a5,
     author = {V. V. Fokicheva},
     title = {Description of singularities for system ``billiard in an ellipse''},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {31--34},
     publisher = {mathdoc},
     number = {5},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2012_5_a5/}
}