@book { InformationseffizienzvonRatingsystemen,
    title = "Informationseffizienz von Ratingsystemen",
    author = "Claudia {Beinert}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832471316",
    url = "https://m.diplom.de/document/222445"
}