@book { ErfolgskontrolleimEventMarketing,
    title = "Erfolgskontrolle im Event-Marketing",
    author = "Astrid {Zander}",
    year = "1999",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832415198",
    url = "https://m.diplom.de/document/217364"
}