@article{MAN_1970__190_162093,
     author = {BIEBERBACH. L.},
     title = {Zwei {Kongruenzs\"atze} f\"ur {Kreisbogendreiecke} in der {Euklidischen} {Ebene.}},
     journal = {Mathematische Annalen},
     pages = {97--118},
     publisher = {mathdoc},
     volume = {190},
     year = {1970},
     zbl = {0195.50601},
     url = {http://geodesic.mathdoc.fr/item/MAN_1970__190_162093/}
}