@Book{Lagally1919,
author  = "Lagally, Max",
title   = "Über orthogonale Kurvensysteme in der Ebene",
year    = "1919",
address = "München",
series  = "Sitzungsberichte",
volume  = "1919,8",
url     = "https://publikationen.badw.de/de/003395411",
}