@article{MAT_1963_7_5_a6,
     author = {S. M. Ulam},
     title = {On some statistical properties of dynamical systems},
     journal = {Matematika},
     pages = {137--142},
     year = {1963},
     volume = {7},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MAT_1963_7_5_a6/}
}