@book { EuropeDay,
    title = "Europe Day",
    subtitle = "How European Integration Got Started",
    author = "Hartmut {Marhold}",
    year = "2022",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b19972",
    url = "https://www.peterlang.com/document/1270153"
}