@Book{Lense1951,
author  = "Lense, Josef",
title   = "Die Winkeldreiteilung des Herrn Sauerbeck",
year    = "1951",
address = "München",
series  = "Sitzungsberichte",
volume  = "1950,7.",
url     = "https://publikationen.badw.de/de/003383642",
}