%0 Journal Article %A B.Helffer %A D. Robert %A X. P. Wang %T Semiclassical analysis of a nonlinear eigenvalue problem and nonanalytic hypoellipticity %J Algebra i analiz %D 2004 %P 320-334 %V 16 %N 1 %U http://geodesic.mathdoc.fr/item/AA_2004_16_1_a10/ %G ru %F AA_2004_16_1_a10