@book { UnitasinLatinAntiquity,
    title = "«Unitas» in Latin Antiquity",
    subtitle = "Four Centuries of Continuity",
    author = "Erik Thaddeus {Walters}",
    year = "2011",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1107994"
}