@article{ELMA_1971__26_141005,
     author = {Wolfgang B\"ohm},
     title = {Die projektiven {Abbildungen} auf einer {Geraden.}},
     journal = {Elemente der Mathematik},
     pages = {32--38},
     publisher = {mathdoc},
     volume = {26},
     year = {1971},
     zbl = {0206.23801},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1971__26_141005/}
}