@Book{Löbell1942,
author  = "Löbell, Frank",
title   = "Grundlinien einer differentiellen Theorie der Somenkongruenzen",
year    = "1942",
address = "München",
series  = "Sitzungsberichte",
volume  = "1942,1",
url     = "https://publikationen.badw.de/en/003399386",
}