%0 Journal Article %A Cardoso, Fernando %A Trèves, François %T A necessary condition of local solvability for pseudo-differential equations with double characteristics %J Annales de l'Institut Fourier %D 1974 %P 225-292 %V 24 %N 1 %I Institut Fourier %U https://doi.org/10.5802/aif.499 %R 10.5802/aif.499 %G en %F AIF_1974__24_1_225_0