@book { VertraglicheGestaltungvonUrlaub, title = "Vertragliche Gestaltung von Urlaub", author = "Miriam {Sprink}", year = "2015", publisher = "Peter Lang Verlag", address = "Berlin, Germany", doi = "10.3726/978-3-653-05346-3", url = "https://www.peterlang.com/document/1049291" }