Haldon, John : "Strategies of Defence, Problems of Security : the Garrisons of Constantinople in the Middle Byzantine Period", in Constantinople and its Hinterland : Papers from the Twenty-Seventh Spring Symposium of Byzantine Studies , Oxford, 1993. [1]
Treadgold, Warren: "Notes on the Number and Organization ot the Ninth Century Byzantine Army", in Greek, Roman and Byzantine Studies , 21 (1980); pp. 269-288. [2]