@book { ApplicabilityofMobileMarketingintheMarketingMixofTradeFairOrganizers,
    title = "Applicability of Mobile Marketing in the Marketing Mix of Trade Fair Organizers",
    author = "Immo {Prenzel}",
    year = "2010",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836645287",
    url = "https://m.diplom.de/document/227737"
}