@book { HelvetischesEuropaEuropischeSchweiz,
    title = "Helvetisches Europa – Europäische Schweiz",
    author = "Tamara {Ehs}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1100001"
}