@book { LaSolidaritdanslUnionEuropenneSolidarittinderEuropischenUnion,
    title = "La Solidarité dans l’Union Européenne- Solidarität in der Europäischen Union",
    author = "Otmar {Seul} and Tomas {Davulis}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1109239"
}