@article{EXMA_1992__1_4_231520,
     author = {Hejhal, Dennis A. and Rackner, Barry N.},
     title = {On the topography of {Maass} waveforms for .},
     journal = {Experimental mathematics},
     pages = {275--305},
     publisher = {mathdoc},
     volume = {1},
     number = {4},
     year = {1992},
     zbl = {0813.11035},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMA_1992__1_4_231520/}
}