TY - JOUR AU - Cardoso, Fernando AU - Trèves, François TI - A necessary condition of local solvability for pseudo-differential equations with double characteristics JO - Annales de l'Institut Fourier PY - 1974 DA - 1974/// SP - 225 EP - 292 VL - 24 IS - 1 PB - Institut Fourier UR - http://www.numdam.org/articles/10.5802/aif.499/ UR - https://zbmath.org/?q=an%3A0273.35058 UR - https://www.ams.org/mathscinet-getitem?mr=50 #2726 UR - https://doi.org/10.5802/aif.499 DO - 10.5802/aif.499 LA - en ID - AIF_1974__24_1_225_0 ER -