@article{GDZPPN00206779X,
title = {Small eigenvalues on Y-pieces and on Riemann surfaces.},
journal = {Commentarii mathematici Helvetici},
volume = {65},
year = {1990},
pages = {603-614},
zbl = {0752.53026},
url = {http://dml.mathdoc.fr/item/GDZPPN00206779X}
}
Schmutz, Paul. Small eigenvalues on Y-pieces and on Riemann surfaces.. Commentarii mathematici Helvetici, Tome 65 (1990) pp. 603-614. http://gdmltest.u-ga.fr/item/GDZPPN00206779X/