%0 Journal Article %A Bérard, Pierre H. %A Helffer, Bernard %T On Courant's Nodal Domain Property for Linear Combinations of Eigenfunctions. I %J Documenta mathematica %D 2018 %P 1561-1585 %V 23 %I mathdoc %U http://geodesic.mathdoc.fr/item/DOCMA_2018__23__a20/ %G en %F DOCMA_2018__23__a20