@article{MM2_1971__5_154059,
     author = {Constantino M. de Barros},
     title = {Calcul diff\'erentiel ext\'erieur de d\'egr\'e arbitraire.},
     journal = {Manuscripta mathematica},
     pages = {59--90},
     publisher = {mathdoc},
     volume = {5},
     year = {1971},
     zbl = {0267.58002},
     url = {http://geodesic.mathdoc.fr/item/MM2_1971__5_154059/}
}