Columbia subject headings:
Russia--Commerce.
Russia--Economic conditions.
Soviet Union--Commerce.
Soviet Union--Economic conditions.
World War, 1914-1918--Blockades.
World War, 1914-1918--Economic aspects--Russia.
World War, 1914-1918--Economic aspects--Soviet Union.
Harvard subject headings:
Soviet Union--Commerce.
Soviet Union--Economic conditions.
World War, 1914-1918--Blockades
World War, 1914-1918--Russia
Princeton subject headings:
Soviet Union--Commerce.
Soviet Union--Economic conditions.
World War, 1914-1918--Blockades.
World War, 1914-1918--Economic aspects--Soviet Union.