@article{IM_1994__115_1_144167,
     author = {H. Iwaniec and W. Duke and J.B. Firedlander},
     title = {A quadratic divisor problem.},
     journal = {Inventiones mathematicae},
     pages = {209--218},
     publisher = {mathdoc},
     volume = {115},
     number = {1},
     year = {1994},
     zbl = {0791.11049},
     url = {http://geodesic.mathdoc.fr/item/IM_1994__115_1_144167/}
}