@article{MAN_1956__132_160511,
     author = {E. Jacobsthal},
     title = {Bemerkungen zu der {Arbeit} des {Herrn} {Bieberbach} \"uber {Kreisbogendreiecke.}},
     journal = {Mathematische Annalen},
     pages = {145--147},
     year = {1956},
     volume = {132},
     zbl = {0070.28601},
     url = {http://geodesic.mathdoc.fr/item/MAN_1956__132_160511/}
}