@book { CommunityFeedbackundVerhalteninsozialenMedien,
    title = "Community-Feedback und Verhalten in sozialen Medien",
    author = "John {Caffier}",
    year = "2017",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/378558"
}