Columbia subject headings:
Permskai︠a︡ oblastʹ (Russia)--History--Sources.
Russia--History--Revolution, 1905-1907--Sources.
Harvard subject headings:
Permskai︠a︡ oblastʹ (Russia)--History--Sources.
Russia--History--Revolution, 1905-1907--Sources.
Princeton subject headings:
Kama River Valley (Russia)--History--Sources.