Columbia subject headings:
Harvard subject headings:
Labor inspection--Portugal--History--20th century.
Labor inspection--Portugal--History--21st century.
Labor policy--Portugal--History--20th century.
Labor policy--Portugal--History--21st century.
Princeton subject headings:
Labor inspection--Portugal--History--20th century.
Labor inspection--Portugal--History--21st century.
Labor policy--Portugal--History--20th century.
Labor policy--Portugal--History--21st century.