@article{02146803, title = {Nodal domain theorems \`a la Courant.}, journal = {Documenta Mathematica}, volume = {9}, year = {2004}, pages = {283-299}, zbl = {1067.35051}, language = {en}, url = {http://dml.mathdoc.fr/item/02146803} }
Ancona, A.; Helffer, B.; Hoffmann-Ostenhof, T. Nodal domain theorems à la Courant.. Documenta Mathematica, Tome 9 (2004) pp. 283-299. http://gdmltest.u-ga.fr/item/02146803/