@book { TheInnovatorsSolution,
    title = "The Innovator's Solution",
    author = "Clayton M. {Christensen} and Michael E. {Raynor} and Kurt {Matzler} and Matthias {Reiss}",
    year = "2018",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1219077"
}