@article{ZNSL_2003_300_a5,
     author = {Y. Baryshnikov and V. Zharnitsky},
     title = {Billiards and nonholonomic distributions},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {56--64},
     publisher = {mathdoc},
     volume = {300},
     year = {2003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2003_300_a5/}
}