Columbia subject headings:
Industrial relations--Argentina--History--20th century--Congresses.
Labor unions--Argentina--History--20th century--Congresses.
Harvard subject headings:
Industrial relations--Argentina--History--20th century--Congresses.
Labor unions--Argentina--History--20th century--Congresses.
Princeton subject headings:
Industrial relations--Argentina--History--20th century--Congresses.
Labor unions--Argentina--History--20th century--Congresses.