@book { Harar,
    title = "Harar",
    subtitle = "Wirtschaftsgeschichte eines Emirats im Horn von Afrika (1825-75)",
    author = "Abdurahmann {Garad}",
    year = "1990",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1077709"
}