@Book{Thoma1954,
author  = "Thoma, Elmar",
title   = "Vollständige Erweiterungen linearer, stetiger Abbildungen",
year    = "1954",
address = "München",
series  = "Sitzungsberichte",
volume  = "1953,7",
url     = "https://publikationen.badw.de/en/003383736",
}