@article{IM_1976__36_142414,
     author = {F. Hirzebruch and D. Zagier},
     title = {Intersection {Numbers} of {Curves} on {Hilbert} {Modular} {Surfaces} and {Modular} {Forms} of {Nebentypus.}},
     journal = {Inventiones mathematicae},
     pages = {57--114},
     publisher = {mathdoc},
     volume = {36},
     year = {1976},
     zbl = {0332.14009},
     url = {http://geodesic.mathdoc.fr/item/IM_1976__36_142414/}
}