Columbia subject headings:
Fraternidad (Organization : Argentina)--History.
Railroads--Employees--Labor unions--Argentina--Córdoba (Province)--History--20th century.
Harvard subject headings:
Fraternidad (Organization : Argentina)--History.
Railroads--Employees--Labor unions--Argentina--Córdoba (Province)--History--20th century.
Princeton subject headings:
Railroads--Employees--Labor unions--Argentina--History.