Petkov, K. (2008). The voices of medieval Bulgaria, seventh-fifteenth century: The records of a bygone culture. Brill.
Lua i Stíl Chicago (17ú heag.)Petkov, Kiril. The Voices of Medieval Bulgaria, Seventh-fifteenth Century: The Records of a Bygone Culture. Leiden ; Boston [Mass.]: Brill, 2008.
Lua MLA (9ú heag.)Petkov, Kiril. The Voices of Medieval Bulgaria, Seventh-fifteenth Century: The Records of a Bygone Culture. Brill, 2008.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.