@book { OptionsscheineaufFrachtraten,
    title = "Optionsscheine auf Frachtraten",
    author = "Philip {Blumenthal}",
    year = "2013",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-02455-5",
    url = "https://www.peterlang.com/document/1047460"
}