Columbia subject headings:
Harvard subject headings:
Burchardus, Vicedominus Argentinensis, active 1175-1194.
Frederick I, Holy Roman Emperor, approximately 1123-1190.
Holy Roman Empire--Foreign relations--Islamic Empire.
Islamic Empire--Description and travel--Early works to 1800.
Islamic Empire--Foreign relations--Holy Roman Empire.
Saladin, Sultan of Egypt and Syria, 1137-1193
Princeton subject headings:
Burchardus, Vicedominus Argentinensis, active 1175-1194.
Frederick I, Holy Roman Emperor, approximately 1123-1190.
Holy Roman Empire--Foreign relations--Islamic Empire.
Islamic Empire--Description and travel--Early works to 1800.
Islamic Empire--Foreign relations--Holy Roman Empire.
Saladin, Sultan of Egypt and Syria, 1137-1193.