@article{FAA_1991_25_3_a5,
     author = {N. I. Chernov},
     title = {New proof of {Sinai's} formula for the entropy of hyperbolic billiard systems. {Application} to {Lorentz} gases and {Bunimovich} stadiums},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {50--69},
     publisher = {mathdoc},
     volume = {25},
     number = {3},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1991_25_3_a5/}
}