@book { FrancisLiebersBriefandPracticalGermanGrammar,
    title = "Francis Lieber’s «Brief and Practical German Grammar»",
    author = "Achim {Kopp}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1105191"
}