@book { RessourcenkonomiedesErdls,
    title = "Ressourcenökonomie des Erdöls",
    author = "Markus {Philippi}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832448967",
    url = "https://m.diplom.de/document/220465"
}