Columbia subject headings:
Harvard subject headings:
Anarchism--Portugal--Porto--History--20th century.
Anarchists--Portugal--Porto--Biography.
Labor movement--Portugal--Porto--History--20th century.
Porto (Portugal)--Guidebooks.
Syndicalists--Portugal--Porto--Biography.
Princeton subject headings:
Anarchism--Portugal--Porto--History--20th century.
Anarchists--Portugal--Porto--Biography.
Guidebooks.
Labor movement--Portugal--Porto--History--20th century.
Porto (Portugal)--Guidebooks.
Syndacalists--Portugal--Porto--Biography.