@book { DieEntstehungderNationenimEuropaderFrhenNeuzeit,
    title = "Die Entstehung der Nationen im Europa der Frühen Neuzeit",
    author = "Annette {Helmchen}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1098947"
}