@book { DasProblemderFinanzierungvonUNFriedensoperationen,
    title = "Das Problem der Finanzierung von UN-Friedensoperationen",
    author = "Klaus Johannes {Müller}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1099480"
}