Columbia subject headings:
Caliphs--Biography.
Hārūn al-Rashīd, Caliph, approximately 763-809.
Islamic Empire--History--750-1258.
Harvard subject headings:
Arabic poetry--750-1258--History and criticism.
Hārūn al-Rashīd, Caliph, approximately 763-809.
Islamic Empire--Kings and rulers--Biography.
Princeton subject headings: