Walls, B. E. (1928). The monks of kublai khan emperor of China: Or the history of the life and travels of rabban sawma, envoy and plenipotentiary of the Mongol Khans to the kings of Europe, and markos who as Maryahbhallaha III became patriarch of the nestorian church in Asia. London: The Relihoins Tract Society.

Walls, Budge E.A. The Monks of Kublai Khan Emperor of China: Or the History of the Life and Travels of Rabban Sawma, Envoy and Plenipotentiary of the Mongol Khans to the Kings of Europe, and Markos Who As Maryahbhallaha III Became Patriarch of the Nestorian Church in Asia. London: The Relihoins Tract Society, 1928.

Walls, Budge E.A. The Monks of Kublai Khan Emperor of China: Or the History of the Life and Travels of Rabban Sawma, Envoy and Plenipotentiary of the Mongol Khans to the Kings of Europe, and Markos Who As Maryahbhallaha III Became Patriarch of the Nestorian Church in Asia. London: The Relihoins Tract Society, 1928.