Columbia subject headings:
Polish people--Brazil--History--Sources.
Polish people--United States--History--Sources.
Harvard subject headings:
Immigrants--Brazil--Correspondence.
Immigrants--United States--Correspondence.
Polish Americans--Correspondence.
Polish Americans--History--19th century--Sources.
Polish people--Brazil--Correspondence.
Polish people--Brazil--History--19th century--Sources.
Princeton subject headings:
Polish people--Brazil--History--Sources.
Polish people--United States--History--Sources.