@article{GDZPPN002219433, title = {\"Uber die isotropen Strahlensysteme.}, journal = {Manuscripta mathematica}, volume = {18}, year = {1976}, pages = {15-24}, zbl = {0325.53010}, url = {http://dml.mathdoc.fr/item/GDZPPN002219433} }
Stamou, Georg. Über die isotropen Strahlensysteme.. Manuscripta mathematica, Tome 18 (1976) pp. 15-24. http://gdmltest.u-ga.fr/item/GDZPPN002219433/