@book { ImmobilienalsAnlageklasse,
    title = "Immobilien als Anlageklasse",
    author = "Simon Alexander {Eckardt}",
    year = "2004",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832480240",
    url = "https://m.diplom.de/document/223262"
}