@Book{Heigel1890,
author  = "Heigel, Karl Theodor von",
title   = "Neue Beiträge zur Charakteristik Kaiser Leopolds I.",
year    = "1890",
address = "München",
series  = "Sitzungsberichte",
volume  = "1890,2,3",
url     = "https://publikationen.badw.de/en/007457799",
}