1. Debbie Williams and Carol Hickson, Aerospace and the Environment, DOT, FAA, U.S. Government Pringing Office, Washington, D.C., 1978.
2. Arthur Wiebe, Project AIMS - Our Wonderful World, Environmental Studies Book 7, Fresno Pacific College, AIMS Education Foundation, 1986
. 3. Henry Smith, Amazing Air, Walker Books Ltd., Great Britian, 1982
. 4. T.J. Chandler, The Air Around Us, Garden City, New York, 1963.
5. L. G. Jacchia, Static Diffusion Models of the Upper Atmosphere with Empirical Temperature Profiles, Smithson. Astrophys. Obs. Spec. Rept. No. 170, Cambridge, Massachusetts, 1964. 6. L. G. Jacchia, Revised Static Models of the Thermosphere and Exosphere with Empirical Temperature Profiles, Smithson. Astrophys. Obs. Spec. Rept. No. 332, 1971.