@Book{Giering1977,
author  = "Giering, Oswald",
title   = "Kennzeichnung von Strahlflächeninvarianten durch Minimaleigenschaften",
year    = "1977",
address = "München",
series  = "Sitzungsberichte",
volume  = "1976,1",
url     = "https://publikationen.badw.de/de/003384259",
}