Columbia subject headings:
Byzantine Empire--Foreign relations--527-1081.
Byzantine Empire--Foreign relations--Islamic Empire.
Diplomatic documents.
Islamic Empire--Foreign relations--750-1258.
Islamic Empire--Foreign relations--Byzantine Empire.
Harvard subject headings:
Byzantine Empire--Foreign relations--527-1081
Byzantine Empire--Foreign relations--Islamic Empire.
Diplomatic documents
Islamic Empire--Foreign relations--750-1258
Islamic Empire--Foreign relations--Byzantine Empire.
Princeton subject headings:
Byzantine Empire--Foreign relations--527-1081.
Byzantine Empire--Foreign relations--Islamic Empire.
Diplomatic documents.
Islamic Empire--Foreign relations--Byzantine Empire.
Islamic Empire--Foreign relations.