Columbia subject headings:
Populism--Spain--History--20th century.
Populism--Spain--History--21st century.
Populism--United States--History--20th century.
Populism--United States--History--21st century.
Harvard subject headings:
Princeton subject headings:
Populism--Spain--History--20th century.
Populism--Spain--History--21st century.
Populism--United States--History--20th century.
Populism--United States--History--21st century.