Beaton, Roderick. "De vulgari eloquentia in Twelfth-Century Byzantium". In Byzantium and the West: c. 850-c. 1250 (J.D. Howard-Johnston, ed. Amsterdam: A.M. Hakkert, 1988) [= Byzantinische Forschungen 13]: 261-268.
Mainly about the Ptochoprodromika.
Reprinted in Roderick Beaton. From Byzantium to Modern Greece: Medieval Texts and their Modern Reception. Variorum Collected Studies Series, CS911 Abingdon, Oxon: Ashgate Publishing, 2008: Ch. I.