@article{05578762,
title = {The Allegretto-Piepenbrink theorem for strongly local Dirichlet forms.},
journal = {Documenta Mathematica},
volume = {14},
year = {2009},
pages = {167-189},
zbl = {1172.35045},
language = {en},
url = {http://dml.mathdoc.fr/item/05578762}
}
Lenz, Daniel; Stollmann, Peter; Veselić, Ivan. The Allegretto-Piepenbrink theorem for strongly local Dirichlet forms.. Documenta Mathematica, Tome 14 (2009) pp. 167-189. http://gdmltest.u-ga.fr/item/05578762/