@article{SM_2009_200_8_a4,
     author = {E. N. Zhabitskaya},
     title = {The average length of reduced regular continued fractions},
     journal = {Sbornik. Mathematics},
     pages = {1181--1214},
     year = {2009},
     volume = {200},
     number = {8},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2009_200_8_a4/}
}