Roman cities in Bulgaria : [Colonia Ulpia Oescensium, Durostorum, Nicopolis ad Istrum, Abritus, Serdica, Pautalia, Nicopolis ad Nestum, Philippopolis, Diocletianopolis, Augusta Traiana, Mesambria] - Ivanov, Rumen Teofilov, 1956- (Prof. Marin Drinov Academic Publishing House, 2012)