@article{GDZPPN00210668X,
title = {Teichm\"uller curves in moduli space, Eisenstein series and an application to triangular billiards.},
journal = {Inventiones mathematicae},
volume = {96},
year = {1989},
pages = {553-584},
zbl = {0676.32006},
url = {http://dml.mathdoc.fr/item/GDZPPN00210668X}
}
Veech, W.A. Teichmüller curves in moduli space, Eisenstein series and an application to triangular billiards.. Inventiones mathematicae, Tome 96 (1989) pp. 553-584. http://gdmltest.u-ga.fr/item/GDZPPN00210668X/