@book { HerstellermarkenversusHandelsmarken,
    title = "Herstellermarken versus Handelsmarken",
    author = "Pia {Eggert}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832488031",
    url = "https://m.diplom.de/document/223983"
}