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