@article{CMH_1940__13_138764,
     author = {Louis Kollros},
     title = {Une propri\'et\'e des vari\'et\'es du second ordre.},
     journal = {Commentarii mathematici Helvetici},
     pages = {108--118},
     publisher = {mathdoc},
     volume = {13},
     year = {1940},
     zbl = {0024.27501},
     url = {http://geodesic.mathdoc.fr/item/CMH_1940__13_138764/}
}