@article{CMH_1942__15_138794,
     author = {Beno Eckmann},
     title = {Systeme von {Richtungsfeldern} in {Sph\"aren} und stetige {L\"osungen} komplexer linearer {Gleichungen.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {1--26},
     publisher = {mathdoc},
     volume = {15},
     year = {1942},
     zbl = {0027.14401},
     url = {http://geodesic.mathdoc.fr/item/CMH_1942__15_138794/}
}