@book { RechtshandbuchfrdieImmobilienpraxis,
    title = "Rechtshandbuch für die Immobilienpraxis",
    author = "Gotthold {Balensiefen} and Christian {Bönker} and Norbert {Geiger} and Wolfgang {Schaller}",
    year = "2011",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1220841"
}