Columbia subject headings:
Izhma Valley--Civilization.
Izhma Valley--Economic conditions.
Izhma Valley--History.
Harvard subject headings:
Izhma (Russia)--Civilization.
Izhma (Russia)--Economic conditions.
Izhma (Russia)--History.
Komi (Russia)--Economic conditions.
Komi (Russia)--History.
Komi (Russia)--Social life and customs.
Princeton subject headings: