@article{ELMA_1975__30_141162,
     author = {Otto Botsch},
     title = {Die {Vierfach-Spiegelungen} an {Geraden.}},
     journal = {Elemente der Mathematik},
     pages = {109--111},
     publisher = {mathdoc},
     volume = {30},
     year = {1975},
     zbl = {0308.50006},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1975__30_141162/}
}