W. L. Petersen,
“The Diatessaron”, in
The Anchor Bible Dictionary, vol. 2, 6 vol., New Haven: Yale University Press, 1992, pp. 189–190.
S. P. Brock,
“The Lost Old Syriac at Luke 1:35 and the Earliest Syriac Terms for the Incarnation”, in
Gospel Traditions in the Second Century,
W. L. Petersen and Aland, B., Eds. Notre Dame: University of Notre Dame press, 1989, pp. 117–131.