Columbia subject headings:
Harvard subject headings:
Abū Bakr, Caliph, -634.
Islamic Empire--Kings and rulers--Biography.
Muḥammad, Prophet, -632--Companions--Biography.
Princeton subject headings:
Abū Bakr, Caliph, -634.
Caliphs--Biography.
Islamic Empire--Kings and rulers--Biography.
Muḥammad, Prophet, -632--Friends and associates--Biography.