Columbia subject headings:
Islamic Empire--History--622-661--Early works to 1800.
ʻUthmān ibn ʻAffān, Caliph, d. 656--Early works to 1800.
Harvard subject headings:
Islamic Empire--History--622-661--Early works to 1800.
ʻUthmān ibn ʻAffān, Caliph, -656--Early works to 1800.
Princeton subject headings: