@article{MZ_1968__106_171001,
     author = {Udo Simon},
     title = {Zur {Relativgeometrie:} {Symmetrische} {Zusammenh\"ange} auf {Hyperfl\"achen.}},
     journal = {Mathematische Zeitschrift},
     pages = {36--46},
     publisher = {mathdoc},
     volume = {106},
     year = {1968},
     zbl = {0164.52002},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__106_171001/}
}