@article{RM_2006_61_1_a9,
     author = {A. Yu. Plakhov},
     title = {Billiards in unbounded domains reversing the direction of motion of a~particle},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {179--180},
     publisher = {mathdoc},
     volume = {61},
     number = {1},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_2006_61_1_a9/}
}