Sources:
- Howard Crosby Butler: Early Churches in Syria. Fourth to Seventh Centuries. Princeton University Press, Princeton 1929, p. 115, ill. 115
- Oskar Wulff, Altchristliche und byzantinische Kunst (Band 1): Die altchristliche Kunst von ihren Anfängen bis zur Mitte des ersten Jahrtausends — Berlin-Neubabelsberg, 1914, p. 210
- http://www.ummeljimal.org/doc/UJ%20Education%20Manual%20V1%20Screen%20EN.pdf
- Butler, H.C. 1913a “Ancient Architecture,” Pp. 149-213 in Syria. Publications of the Princeton University Archaeological Expedition to Syria (Div. II, Part 3, Umm Idj-Djimal, Leyden) 149-213.