Impacts of airborne pollutants on wilderness areas along the Minnesota-Ontario border /

Mode of access: Internet.

Better enforcement of car emission standards - a way to improve air quality.

Mode of access: Internet.

Limits of allowable concentrations of atmospheric pollutants.

"Three reports issued by the U.S.S.R. Committee on the Determination of Limits of Allowable Concentrations of Atmospheric Pollutants. Published by the State Publishing House of Medical Literature, Medgiz of Moscow, 1952-1957."

Atmosphere-surface exchange of particulate and gaseous pollutants (1974) : proceedings of a symposium held at Richland, Washington, September 4-6, 1974 /

Mode of access: Internet.