Columbia subject headings:
Gregoras, Nicephorus, 1295-1359 or 1360.
Human geography.
Physical geography.
Harvard subject headings:
Gregoras, Nicephorus, 1295-1359 or 1360--Contributions in human geography.
Gregoras, Nicephorus, 1295-1359 or 1360--Contributions in physical geography.
Princeton subject headings:
Geography, Medieval.
Gregoras, Nicephorus, 1295-1359 or 1360--Knowledge--Geography.