Columbia subject headings:
Cooperation--Russia (Federation)--Pskovskai︠a︡ oblastʹ--History--19th century.
Cooperation--Russia (Federation)--Pskovskai︠a︡ oblastʹ--History--20th century.
Cooperation--Russia--History--19th century.
Cooperation--Russia--History--20th century.
Pskovskai︠a︡ gubernii︠a︡ (R.S.F.S.R.)--Economic conditions.
Russia--Economic conditions--1861-1917.
Harvard subject headings:
Cooperation--Russia (Federation)--Pskovskai︠a︡ oblastʹ--History--19th century.
Cooperation--Russia (Federation)--Pskovskai︠a︡ oblastʹ--History--20th century.
Cooperation--Russia--History--19th century.
Cooperation--Russia--History--20th century.
Pskovskai︠a︡ gubernii︠a︡ (R.S.F.S.R.)--Economic conditions.
Russia--Economic conditions--1861-1917.
Princeton subject headings:
Cooperation--Russia (Federation)--Pskovskai︠a︡ oblastʹ--History--19th century.
Cooperation--Russia (Federation)--Pskovskai︠a︡ oblastʹ--History--20th century.
Cooperation--Russia--History--19th century.
Cooperation--Russia--History--20th century.
Pskovskai︠a︡ gubernii︠a︡ (R.S.F.S.R.)--Economic conditions.
Russia--Economic conditions--1861-1917.