@article{ELMA_1968__23_140885,
     author = {K. Kopfermann},
     title = {\"Uber {Dreiecke.}},
     journal = {Elemente der Mathematik},
     pages = {49--60},
     year = {1968},
     volume = {23},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1968__23_140885/}
}