Columbia subject headings:
Detroit River (Mich. and Ont.)
Detroit River.
International rivers.
Niagara River (N.Y. and Ont.)
Saint Clair River (Mich. and Ont.)
Sewage disposal.
St. Clair River (Wis. and Minn.)
Water--Pollution.
Harvard subject headings:
Detroit River.
Niagara River (N.Y. and Ont.)
Saint Clair River (Mich. and Ont.)
Sewage disposal
St. Claire River.
Water--Pollution
Princeton subject headings:
Detroit River.
Niagara River (N.Y. and Ont.)
Sewage disposal.
St. Claire River.
Water--Pollution.