@book { DerspanischeMaklervertrag,
    title = "Der spanische Maklervertrag ",
    subtitle = "Unter besonderer Berücksichtigung des spanischen Immobilienmaklervertrages",
    author = "Marcus {Iske}",
    year = "2017",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b11446",
    url = "https://www.peterlang.com/document/1050615"
}