@article{DAN_1993_333_2_a2,
     author = {A. A. Karatsuba},
     title = {Distribution of inverse values in a residue ring modulo a given},
     journal = {Doklady Akademii Nauk},
     pages = {138--139},
     publisher = {mathdoc},
     volume = {333},
     number = {2},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1993_333_2_a2/}
}