@book { SuchmaschinenMarketingalsTeildesOnlineMarketings,
    title = "Suchmaschinen-Marketing als Teil des Online-Marketings",
    author = "Jana {Heinrich}",
    year = "2010",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836647175",
    url = "https://m.diplom.de/document/227804"
}