@book { TheoretischeGrundlagenderFiscalPolicy,
    title = "Theoretische Grundlagen der 'Fiscal Policy'",
    author = "Helmut {Hesse} and Horst {Keppler} and Andreas {Schuseil}",
    year = "2015",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1220843"
}