Columbia subject headings:
Railroads--Russia--History.
Russia--History--Nicholas I, 1825-1855.
Harvard subject headings:
Railroad travel--Russia--History.
Railroads--Russia--History.
Russia--History--Nicholas I, 1825-1855.
Princeton subject headings:
Railroad travel--Russia--History.
Railroads--Russia--History.
Russia--History--Nicholas I, 1825-1855.