@Book{Lindemann1923,
author  = "Lindemann, Ferdinand",
title   = "Zur Trigonometrie im nicht-euklidischen Raume",
year    = "1923",
address = "München",
series  = "Sitzungsberichte",
volume  = "1922,10",
url     = "https://publikationen.badw.de/en/003399267",
}