@article{CHEB_2021_22_5_a4,
     author = {V. V. Vedyushkina and V. A. Kibkalo and S. E. Pustovoitov},
     title = {Realization of focal singularities of integrable systems using billiard books with a {Hooke} potential field},
     journal = {\v{C}eby\v{s}evskij sbornik},
     pages = {44--57},
     publisher = {mathdoc},
     volume = {22},
     number = {5},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CHEB_2021_22_5_a4/}
}