Columbia subject headings:
Africa--Relations--Egypt.
Arabian Peninsula--History.
Egypt--History--To 640 A.D.
Egypt--Relations--Africa.
Ethiopia--History--To 1490.
Harvard subject headings:
Arabian Peninsula--History.
Egypt--History--To 640 A.D.
Ethiopia--History--To 1400.
Princeton subject headings:
Africa--Relations--Egypt.
Egypt--Relations--Africa.