@Book{Perron1929,
author  = "Perron, Oskar",
title   = "Die Winkeldreiteilung des Schneidermeisters Kopf",
year    = "1929",
address = "München",
series  = "Sitzungsberichte",
volume  = "1929,18",
url     = "https://publikationen.badw.de/en/003383299",
}