@article{SM_1971_14_2_a0,
     author = {M. V. Jakobson},
     title = {On smooth mappings of the circle into itself},
     journal = {Sbornik. Mathematics},
     pages = {161--185},
     publisher = {mathdoc},
     volume = {14},
     number = {2},
     year = {1971},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1971_14_2_a0/}
}