@article{CMH_1971__46_139493,
     author = {B. Malgrange},
     title = {Ouverts concaves et th\'eor\`emes de dualit\'e pour les syst\`emes diff\'erentiels \`a coefficients constants},
     journal = {Commentarii mathematici Helvetici},
     pages = {487--499},
     publisher = {mathdoc},
     volume = {46},
     year = {1971},
     zbl = {0229.35015},
     url = {http://geodesic.mathdoc.fr/item/CMH_1971__46_139493/}
}