@book { EntwicklungstendenzeninderinternationalenPreisdifferenzierung,
    title = "Entwicklungstendenzen in der internationalen Preisdifferenzierung",
    author = "Marcus {Burkert}",
    year = "1999",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832418106",
    url = "https://m.diplom.de/document/217665"
}