@book { DieresextracommerciumimrmischenRecht,
    title = "Die «res extra commercium» im römischen Recht",
    author = "Gero {Alvensleben}",
    year = "2019",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b14906",
    url = "https://www.peterlang.com/document/1057011"
}