@article{JRAM_1989__395_153118,
     author = {Svetlana Katok},
     title = {Finite spanning sets for cusp forms and a related geometric result.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {186--195},
     publisher = {mathdoc},
     volume = {395},
     year = {1989},
     zbl = {0666.10016},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1989__395_153118/}
}