Columbia subject headings:
Grain trade--Government policy--Canada--Congresses.
Grain trade--Government policy--United States--Congresses.
Grain--Canada--Congresses.
Grain--United States--Congresses.
Harvard subject headings:
Grain trade--Government policy--Canada--Congresses.
Grain trade--Government policy--United States--Congresses.
Grain--Canada--Congresses.
Grain--United States--Congresses.
Princeton subject headings:
Grain trade--Government policy--Canada--Congresses.
Grain trade--Government policy--United States--Congresses.
Grain--Canada--Congresses.
Grain--United States--Congresses.