1. Clean Air Act (42 U.S.C. 1857 et seq.) includes the Clean Air Act of 1963 (P.L. 88-206) and amendments made by the Motor Vehicle Air Pollution Control Act (P.L. 89-272 October 20 1965) the Clean Air Act Amendments of 1966 (P.L. 89-675 October 15 1966) the Air Quality Act of 1967 (P.L. 90-148 November 21 1967) and the Clean Air Amendments of 1970 (P.L. 91-604 December 31 1970).
2. The reduction of nitric oxide in automobile emissions-stabilization of catalysts containing ruthenium;Shelef M.;Platinum Met. Rev.,1974
3. Bond G. C. Catalysis by Metals Academic Press New York-London 1962.
4. Anonymous. GM sets 10-year pact to purchase platinum for pollution control. Wall Street Journal 3-Star Eastern Ed. p. 15 (December 12 1972).
5. Beamish F. E. The Analytical Chemistry of the Noble Metals Pergamon Press New York-London 1965.