Columbia subject headings:
Harvard subject headings:
Industries--Russia (Federation)--Leningradskai︠a︡ oblastʹ--Congresses.
Leningradskai︠a︡ oblastʹ (Russia)--Economic conditions--Congresses.
Princeton subject headings:
Industries--Russia (Federation)--Leningradskai︠a︡ oblastʹ--Congresses.
Leningradskai︠a︡ oblastʹ (Russia)--Economic conditions--Congresses.