@article{IM2_1988_31_2_a3,
     author = {A. A. Karatsuba},
     title = {The distribution of pairs of quadratic residues and nonresidues of a~special form},
     journal = {Izvestiya. Mathematics },
     pages = {307--323},
     publisher = {mathdoc},
     volume = {31},
     number = {2},
     year = {1988},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1988_31_2_a3/}
}