@book { ControllingRelevancelost,
    title = "Controlling - Relevance lost?",
    author = "Ronald {Gleich} and Reinhold {Mayer} and Klaus {Möller} and Mischa {Seiter}",
    year = "2012",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1220787"
}