@book { Immobilienwirtschaft,
    title = "Immobilienwirtschaft",
    subtitle = "Handbuch für Studium und Praxis",
    author = "Hanspeter {Gondring} and Anjulie {Timur}",
    year = "2023",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1403561"
}