Brand 1989, стр. 5. Brand, Charles M. The Turkish Element in Byzantium, Eleventh-Twelfth Centuries // Dumbarton Oaks Papers 43. Washington, District of Columbia, Dumbarton Oaks, Trustees for Harvard University, 1989. DOI:10.2307/1291603. с. 1–25.
Brand 1989, с. 6. Brand, Charles M. The Turkish Element in Byzantium, Eleventh-Twelfth Centuries // Dumbarton Oaks Papers 43. Washington, District of Columbia, Dumbarton Oaks, Trustees for Harvard University, 1989. DOI:10.2307/1291603. с. 1–25.