Columbia subject headings:
Drainage laws--Cases.
Drainage--Iowa.
Forms (Law)--Iowa.
Irrigation laws--Cases.
Natural gas--Cases.
Petroleum industry and trade--Cases.
Water--Law and legislation--Cases.
Harvard subject headings:
Drainage laws--Cases.
Drainage--Iowa.
Forms (Law)--Iowa.
Irrigation laws--Cases.
Mining law--Canada--Cases.
Mining law--Cases.
Mining law--United States--Cases.
Natural gas--Cases.
Petroleum industry and trade--Cases.
Water--Law and legislation--Canada--Cases.
Water--Law and legislation--Cases.
Water--Law and legislation--United States--Cases.
Princeton subject headings: