Popović 1999, p. 37–38, 155–161, 297–298, 400. Popović, Marko (1999). Tvrđava Ras [The Fortress of Ras] (in Serbian). Belgrade: Archaeological Institute. ISBN9788680093147.
Curta 2019, pp. 659–660:Ras had been rebuilt in the late 1160s, with new building added within ramparts, including a palatial compound (..) In short, Ras has rightly been viewed as a royal residence built by Nemanja and then used by his immediate successorts. But it was certainly not the permanent residence of the grand Zupan, for Nemanja is known to have had 'palaces' in various other parts in this realm, including Kotor. Curta, Florin (2019). Eastern Europe in the Middle Ages (500-1300). Leiden and Boston: Brill. ISBN978-90-04-39519-0.
Dimnik 1995, p. 268:Vukan assumed the title grand župan and established his capital at the fortress of Ras after which Raška was named. Dimnik, Martin (1995). "Kievan Rus', the Bulgars and the southern Slavs, c. 1020-c. 1200". The New Cambridge Medieval History. Vol. 4/2. Cambridge: Cambridge University Press. pp. 254–276. ISBN978-0-521-41411-1.
Curta 2019, p. 656:Shortly after his victory over the Pechenegs in 1122, Emperor John II Comnenus organized a punitive expedition against the Serbs. The exact reason for that is unknown, but it is most likely at that time that the Byzantine border fort at Ras (near Novi Pazar, in southern Serbia) was burned (Fig. 30.1) Curta, Florin (2019). Eastern Europe in the Middle Ages (500-1300). Leiden and Boston: Brill. ISBN978-90-04-39519-0.
Dimnik 1995, p. 270:In 1190, after Frederick I had crossed the Bosphorus, Emperor Isaac II Angelus marched against Nemanja, defeated him on the River Morava, and forced him to make peace. The terms of the agreement suggest that the Byzantine victory had been indecisive: the emperor acknowledged Raška's independence (..) Dimnik, Martin (1995). "Kievan Rus', the Bulgars and the southern Slavs, c. 1020-c. 1200". The New Cambridge Medieval History. Vol. 4/2. Cambridge: Cambridge University Press. pp. 254–276. ISBN978-0-521-41411-1.
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). Зборник радова Византолошког института. 50 (1): 449–460.
Ivanišević & Krsmanović 2013, p. 451:In addition to this, Anne Komnene, who gave detailed accounts of Alexios’ confl icts with the Rascian župan Vukan (1091, 1093–1094), does not mention Ras in any of her writings. On the other hand, the Chronicle of Dioclea states that in the 1080s Bodin conquered Rascia, the region where – with his help – župan Vukan and his brother Marko established their rule;13 however, the question remains whether the Byzantine border fortress became a part of Serbia at this time. The Serbian conquest of Ras is confirmed at a later date, during the reign of John II Komnenos (1118–1143). John Kinnamos relates the Serbian conquest and burning down of the Byzantine Ras (circa 1127–1129), which prompted the Emperor to punish Kritoplos, the commander of the fortress. Ivanišević, Vujadin; Krsmanović, Bojana (2013). "Byzantine Seals from the Ras Fortress"(PDF). Зборник радова Византолошког института. 50 (1): 449–460.