@Book{Lipps1904,
author  = "Lipps, Theodor",
title   = "Ueber einfachste Formen der Raumkunst",
year    = "1904",
address = "München",
series  = "Abhandlungen",
volume  = "23,[5] : 3. Abt.",
url     = "https://publikationen.badw.de/de/003197803",
}