@book { OnlinePRimZeitaltervonSocialMedia,
    title = "Online PR im Zeitalter von Social Media",
    author = "Katharina {Wimmer}",
    year = "2015",
    publisher = "BACHELOR + MASTER PUBLISHING",
    address = "Hamburg, Deutschland",
    url = "https://m.bachelor-master-publishing.de/document/297210"
}