1. Jaffe, L. S.: 1968, ‘Ambient Carbon Monoxide and its Fate in the Atmosphere’, J. Air Pollution Control Assoc. 18 (8), 534–540.
2. Air Quality Criteria for Carbon Monoxide: 1970, National Air Pollution Control Administration Publication No. AP-62. Environmental Health Service, Public Health Service. U.S. Department of Health, Education and Welfare, Washington, D.C., March 1970.
3. Robinson, E. and Robbins, R. E.: 1968, Sources, Abundance and Fate of Gaseous Atmosphere Pollutants. Stanford Research Institute Project Pr-6755. Menlo Park, Calif.
4. Grob, K.: 1968, ‘Gaseous Components of Tobacco Smoke’, in Toward a Less Harmful Cigarette, Monograph No. 28. National Cancer Institute. National Cancer Institute, Bethesda, Md., p. 215.
5. Federal Trade Commission: 1969, Personal communication.