Columbia subject headings:
Canada--Emigration and immigration--History--20th century.
Poland--Emigration and immigration--History--20th century.
Polish people--Canada--History--20th century.
Harvard subject headings:
Canada--Emigration and immigration--History--20th century.
Immigrants--Canada--History--20th century.
Poland--Emigration and immigration--History--20th century.
Polish people--Canada--History--20th century.
Princeton subject headings:
Canada--Emigration and immigration--History--20th century.
Poland--Emigration and immigration--History--20th century.
Polish people--Canada--History--20th century.