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Stojkovski 2020, p.153. Stojkovski, Boris (2020). "Byzantine military campaigns against Serbian lands and Hungary in the second half of the eleventh century.". In Theotokis, Georgios; Meško, Marek (eds.). War in Eleventh-Century Byzantium. Routledge. ISBN978-0429574771.
Mrkobrad 1997, p.204. Mrkobrad, Dušan (1997). "Рас-Постење: фазе развоја утврђења"[Ras-Postenje: Phases in the Development of the Fortress]. Proceedings of the Institute of Byzantine Studies (36). Vizantološki institut SANU: 203–219.
Bulić 2013, p.222, Mrkobrad 1997, pp.203–217 Mrkobrad, Dušan (1997). "Рас-Постење: фазе развоја утврђења"[Ras-Postenje: Phases in the Development of the Fortress]. Proceedings of the Institute of Byzantine Studies (36). Vizantološki institut SANU: 203–219.
Mrkobrad 1997, p.212. Mrkobrad, Dušan (1997). "Рас-Постење: фазе развоја утврђења"[Ras-Postenje: Phases in the Development of the Fortress]. Proceedings of the Institute of Byzantine Studies (36). Vizantološki institut SANU: 203–219.