@article{IM_1981__64_142819,
     author = {D. Zagier and W. Kohnen},
     title = {Values of {L-series} of {Modular} {Forms} at the {Center} of the {Critical} {Strip.}},
     journal = {Inventiones mathematicae},
     pages = {175--198},
     publisher = {mathdoc},
     volume = {64},
     year = {1981},
     zbl = {0468.10015},
     url = {http://geodesic.mathdoc.fr/item/IM_1981__64_142819/}
}