@book { HeinrichRaspeLandgrafvonThringenundrmischerKnig12271247, title = "Heinrich Raspe – Landgraf von Thüringen und römischer König (1227-1247)", author = "Matthias {Werner}", year = "2021", publisher = "Peter Lang Verlag", address = "Berlin, Germany", url = "https://www.peterlang.com/document/1095027" }