1. 1962. Committee on Threshold Limit Values Documentation of Threshold Limit Values.American Conference of Governmental Industrial Hygienists, 1014 Broadway, Cincinnati 2, Ohio,
2. Patty , F. A. 1963.Industrial Hygiene and Toxicology., 2nd Ed., Vol. II, 1972New York: Interscience Publishers.
3. EFFECT OF POSSIBLE SMOG IRRITANTS ON HUMAN SUBJECTS