@book { berdasAlter, title = "Über das Alter", subtitle = "Eine historisch-kritische Analyse der Schriften Über das Alter/περὶ γήρως von Musonius, Favorinus und Iuncus", author = "Markus {Sigismund}", year = "2003", publisher = "Peter Lang Verlag", address = "Berlin, Germany", url = "https://www.peterlang.com/document/1096003" }