@article{ZNSL_1981_112_a0,
     author = {V. A. Bykovskii},
     title = {Asymptotic properties of integral points $(a_1,a_2)$, satisfying the congruence $a_1a_2\equiv l(q)$},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {5--25},
     publisher = {mathdoc},
     volume = {112},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1981_112_a0/}
}