@book { PreludetoConstantine,
    title = "Prelude to Constantine",
    subtitle = "The Abgar Tradition in Early Christianity",
    author = "Alexander {Mirkovic}",
    year = "2004",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1097727"
}