Columbia subject headings:
Harvard subject headings:
Asia, Central--History.
Khiva (Uzbekistan)--History.
Khorezmskai︠a︡ Sovetskai︠a︡ Sot︠s︡ialisticheskai︠a︡ Respublika--History.
Soviet Union--History--Revolution, 1917-1921.
Princeton subject headings:
Khorazm oblasti (Uzbekistan)--History.