Nicéphore Calliste Xanthopoulos, imitator Gregorii Nazianzeni? - Somers, Véronique (Gastgeber, Christian 1970- (edt), Panteghini, Sebastiano (edt), Ecclesiastical history and Nikephoros Kallistou Xanthopoulos: proceedings of the international symposium, Vienna 15th-16th december 2011, 2015)