Langdon, J. S. (1992). Byzantium's last imperial offensive in Asia Minor: The documentary evidence for and hagiographical lore about John III Ducas Vatatzes' Crusade against the Turks, 1222 or 1225 to 1231. Caratzas.
Chicago Style (17th ed.) CitationLangdon, John S. Byzantium's Last Imperial Offensive in Asia Minor: The Documentary Evidence for and Hagiographical Lore About John III Ducas Vatatzes' Crusade Against the Turks, 1222 or 1225 to 1231. New Rochelle, NY: Caratzas, 1992.
MLA (9th ed.) CitationLangdon, John S. Byzantium's Last Imperial Offensive in Asia Minor: The Documentary Evidence for and Hagiographical Lore About John III Ducas Vatatzes' Crusade Against the Turks, 1222 or 1225 to 1231. Caratzas, 1992.
Warning: These citations may not always be 100% accurate.