Columbia subject headings:
Minas Gerais (Brazil)--Economic conditions.
Slave labor--Brazil--Minas Gerais--History.
Harvard subject headings:
Freed persons--Brazil--Minas Gerais--History--19th century.
Slave labor--Brazil--Minas Gerais--History--19th century.
Working class--Brazil--Minas Gerais--History--19th century.
Princeton subject headings:
Freed persons--Brazil--Minas Gerais--History--19th century.
Slave labor--Brazil--Minas Gerais--History--19th century.
Working class--Brazil--Minas Gerais--History--19th century.