After working on a collaborative volume on a Coptic source ("Eudoxia and the Holy Sepulchre: A Constantinian Legend in Coptic" (Milan: Cisalpino, 1980), he produced a series of important articles such as “Eusebius on the True Cross,” "Journal of Ecclesiastical History" 36 (1985): 1-22; “Suggestions of dates in Constantine's Oration to the Saints,” "American Journal of Philology" 106 (1985): 335-349; “Athanasius' first exile,” "Greek, Roman, and Byzantine Studies" 27 (1986): 193-204; “What Eusebius knew: The genesis of the Vita Constantini,” "Classical Philology" 83 (1988): 20-38; “Policy and belief in Constantine's Oration to the Saints,” "Studia Patristica" 19 (1989): 43-51; “Constantine and Consensus,” "Church History" 64 (1995) 1-15; and “Lambs into Lions: explaining early Christian intolerance” "Past &Present" 153 (1996) 3-36.