@article{SM_2022_213_2_a0,
     author = {G. V. Belozerov},
     title = {Topological classification of billiards bounded by confocal quadrics in three-dimensional {Euclidean} space},
     journal = {Sbornik. Mathematics},
     pages = {129--160},
     publisher = {mathdoc},
     volume = {213},
     number = {2},
     year = {2022},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2022_213_2_a0/}
}