Columbia subject headings:
Belgium--Politics and government.
Catholic Church--Belgium.
Church and state--Belgium.
Labor--Religious aspects--Christianity--Belgium.
Harvard subject headings:
Belgium--Politics and government.
Catholic Church--Belgium.
Catholic labor unions--Belgium--History--20th century--Sources.
Church and state--Belgium.
Labor--Belgium--Religious aspects--Christianity--History--20th century--Sources.
Labor--Religious aspects--Christianity--Belgium.
Princeton subject headings:
Catholic labor unions--Belgium--History--20th century--Sources.
Labor movement--Belgium--History--20th century--Sources.
Labor movement--Belgium--Religious aspects--Christianity--History--20th century--Sources.
Labor--Religious aspects--Christianity--Belgium--History--20th century--Sources.
Secrétariat général des œuvres sociales (Belgium)--History--Sources.