1. U.S. Environmental Protection Agency, “Protecting Visibility,” EPA-450/5–79-008. Office of Air Quality Planning and Standards, Research Triangle Park, NC, 1979.
2. “Smoke, Dust and Haze.”;Friedlander,1977
3. “Vision through the Atmosphere.”;Middleton,1952
4. Scattering in the atmosphere of earth and planets;Van De Hulst,1949
5. Separation of the Absorption Spectra of NO2 and N2O4 in the Range of 2400–5000A