Columbia subject headings:
Madrid (Spain)--Politics and government--20th century.
Political participation -- Spain -- Madrid -- History--Spain--Madrid--History.
Socialism--Spain--Madrid.
Harvard subject headings:
Madrid (Spain)--Politics and government--20th century.
Political participation--Spain--Madrid--History--20th century.
Socialism--Spain--Madrid--History--20th century.
Princeton subject headings:
Madrid (Spain)--Politics and government--20th century.
Political participation--Spain--Madrid--History.
Socialism--Spain--Madrid--History.