@book { InvisibleLanguagesintheNineteenthCentury,
    title = "Invisible Languages in the Nineteenth Century",
    author = "Anna {Havinga} and Nils {Langer}",
    year = "2015",
    publisher = "Peter Lang Verlag",
    address = "Oxford, United Kingdom",
    doi = "10.3726/978-3-0353-0760-3",
    url = "https://www.peterlang.com/document/1053459"
}