Columbia subject headings:
Caucasus, Northern (Russia)--Economic conditions--1861-1917.
Don River Region (Russia)--Economic conditions--1861-1917.
Harvard subject headings:
Caucasus, Northern (Russia)--Economic conditions.
Don River Valley (Russia)--Economic conditions.
Princeton subject headings:
Caucasus, Northern (Russia)--Economic conditions.
Don River Valley (Russia)--Economic conditions.