@article{IM_1993__112_3_144102,
     author = {Benedict H. Gross and Kevin Keating},
     title = {On the intersection of modular correspondences.},
     journal = {Inventiones mathematicae},
     pages = {225--246},
     publisher = {mathdoc},
     volume = {112},
     number = {3},
     year = {1993},
     zbl = {0811.11026},
     url = {http://geodesic.mathdoc.fr/item/IM_1993__112_3_144102/}
}