@article{MZ_1965__87_170369,
     author = {G\"unter Ewald},
     title = {Erweiterungen projektiv-geometrischer {Verb\"ande.}},
     journal = {Mathematische Zeitschrift},
     pages = {101--114},
     publisher = {mathdoc},
     volume = {87},
     year = {1965},
     zbl = {0124.12903},
     url = {http://geodesic.mathdoc.fr/item/MZ_1965__87_170369/}
}