@book { InternationaleHandelsgeschfte,
    title = "Internationale Handelsgeschäfte",
    author = "Rainer {Gildeggen} and Andreas {Willburger}",
    year = "2017",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1221271"
}