Popović 1999, p. 292–294, 394–397. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
Popović 1999, p. 155–161, 297, 400. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
Popović 1999, p. 37, 297–298, 400. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
Popović 1999, p. 139–161, 297, 400–401. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
Popović 1999, p. 162, 299, 402–403. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
Popović 1999, p. 38, 302–303, 306. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
Popović 1999, p. 295–296, 399–400. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
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.
Ivanišević & Krsmanović 2013, p. 451–452:Recently found seals on the site The Fortress of Ras support the opinion that the Byzantine Empire held dominant (but perhaps not continuous) control over Ras during Alexios' reign Ivanišević, Vujadin; Krsmanović, Bojana (2013). "Byzantine seals from the Ras fortress"(PDF). Recueil des travaux de l'Institut d'études byzantines. 50 (1): 449–460. doi:10.2298/ZRVI1350449I.
Ivanišević & Krsmanović 2013, p. 451–452:Recently found seals on the site The Fortress of Ras support the opinion that the Byzantine Empire held dominant (but perhaps not continuous) control over Ras during Alexios' reign Ivanišević, Vujadin; Krsmanović, Bojana (2013). "Byzantine seals from the Ras fortress"(PDF). Recueil des travaux de l'Institut d'études byzantines. 50 (1): 449–460. doi:10.2298/ZRVI1350449I.