@book { DerEUVerwaltungsvertrag, title = "Der EU-Verwaltungsvertrag", author = "Titos {Markopoulos}", year = "2012", publisher = "Peter Lang Verlag", address = "Berlin, Germany", doi = "10.3726/978-3-653-01188-3", url = "https://www.peterlang.com/document/1045753" }