@book { GrafGerhardderMutigevonOldenburgundDelmenhorst14301500,
    title = "Graf Gerhard der Mutige von Oldenburg und Delmenhorst (1430-1500)",
    author = "Franziska {Nehring}",
    year = "2012",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-01632-1",
    url = "https://www.peterlang.com/document/1047115"
}