Columbia subject headings:
Harvard subject headings:
Cabinet system--Portugal--History--20th century.
Cabinet system--Portugal--History--21st century.
Executive power--Portugal--History--20th century.
Executive power--Portugal--History--21st century.
Presidents--Portugal--History--20th century--Chronology.
Presidents--Portugal--History--21st century--Chronology.
Princeton subject headings:
Cabinet system--Portugal--History--20th century.
Cabinet system--Portugal--History--21st century.
Executive power--Portugal--History--20th century.
Executive power--Portugal--History--21st century.
Presidents--Portugal--History--20th century--Chronology.
Presidents--Portugal--History--21st century--Chronology.