@article{JDM_1939__49_146219,
     author = {Georges de Rham},
     title = {Sur un proc\`ede de formation d'invariants int\'egraux.},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {156--161},
     publisher = {mathdoc},
     volume = {49},
     year = {1939},
     zbl = {0021.42903},
     url = {http://geodesic.mathdoc.fr/item/JDM_1939__49_146219/}
}