C. Olsen: Celibacy and Religious Traditions. Oxford University Press. 1st Ed. 2007. Pg. 143–144
Alexēs G. K. Savvidēs, Byzantium in the Near East: Its Relations with the Seljuk Sultanate of Rum in Asia Minor, The Armenians of Cilicia and The Mongols, A.D. c. 1192-1237, Kentron Vyzantinōn Ereunōn, 1981, p. 116.