Metcalf, W.E. The Silver Coinage of Cappadocia, Vespasian-Commodus. ANSNNM 166. (New York, 1996).
Available online: https://archive.org/details/silvercoinageofc00metc
Metcalf Hoard is also included in this volume.
Also see:
References by David Michael Metcalf
Metcalf Ash
Metcalf Balkans
Metcalf CLC
Metcalf Crusaders
Metcalf Jerusalem
Metcalf Latin Imitative
Metcalf MN XX
Metcalf NC 1969
Metcalf Origins
Metcalf SE Europe
Metcalf Seals
Metcalf Thrymsas