@article{GDZPPN002376326, title = {Differentialgeometrie der Strahenkomplex I}, journal = {Mathematische Zeitschrift}, volume = {40}, year = {1936}, pages = {560-581}, zbl = {0012.31402}, url = {http://dml.mathdoc.fr/item/GDZPPN002376326} }
Haack, W. Differentialgeometrie der Strahenkomplex I. Mathematische Zeitschrift, Tome 40 (1936) pp. 560-581. http://gdmltest.u-ga.fr/item/GDZPPN002376326/