Columbia subject headings:
Science--Byzantine Empire--History.
Harvard subject headings:
Byzantine Empire--History--Palaeologi dynasty, 1259-1448.
Gregoras, Nicephorus, 1295-1359 or 1360
Metochites, Theodoros, -1332.
Nicephorus, Blemmydes, 1197-1272.
Pachymeres, George, 1242-approximately 1310
Science--Byzantine Empire--History.
Scientists--Byzantine Empire--History.
Princeton subject headings: