@article{GDZPPN002192756,
title = {Minimum of quadratic forms with respect to Fuchsian groups. I.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {281},
year = {1976},
pages = {341-368},
zbl = {0332.10015},
url = {http://dml.mathdoc.fr/item/GDZPPN002192756}
}
Schmidt, Asmus L. Minimum of quadratic forms with respect to Fuchsian groups. I.. Journal für die reine und angewandte Mathematik, Tome 281 (1976) pp. 341-368. http://gdmltest.u-ga.fr/item/GDZPPN002192756/