@article{GDZPPN002333783,
title = {Rational period functions and indefinite binary quadratics forms. I.},
journal = {Mathematische Annalen},
volume = {287},
year = {1990},
pages = {697-708},
zbl = {0673.10018},
url = {http://dml.mathdoc.fr/item/GDZPPN002333783}
}
Choie, YoungJu; Parson, L. Alayne. Rational period functions and indefinite binary quadratics forms. I.. Mathematische Annalen, Tome 287 (1990) pp. 697-708. http://gdmltest.u-ga.fr/item/GDZPPN002333783/