Columbia subject headings:
Populism--United States--History--20th century.
Recall--United States--History--20th century.
Referendum--United States--History--20th century.
Harvard subject headings:
Populism--United States--History--20th century.
Recall--United States--History--20th century.
Referendum--United States--History--20th century.
Princeton subject headings:
Populism--United States--History--20th century.
Recall--United States--History--20th century.
Referendum--United States--History--20th century.