@book { StrategischesManagementinreifenundschrumpfendenBranchen,
    title = "Strategisches Management in reifen und schrumpfenden Branchen",
    author = "Kalin {Tsvetkov}",
    year = "2015",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/294224"
}