@article{PA_2016_5_1_a2,
     author = {B. M. Shirokov and L. A. Gromakovskaya},
     title = {Distribution of values of the sum of unitary divisors in residue classes},
     journal = {Problemy analiza},
     pages = {31--44},
     publisher = {mathdoc},
     volume = {5},
     number = {1},
     year = {2016},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PA_2016_5_1_a2/}
}