@article{JRAM_1872__74_148182,
     author = {Emil Weyr},
     title = {Ueber die {Anzahl} der {Doppelnormalen} einer rationaler {Raumcurve.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {279--280},
     publisher = {mathdoc},
     volume = {74},
     year = {1872},
     zbl = {04.0316.02},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1872__74_148182/}
}