Bernstein, D. and Peggy Nash. 1999. Essentials of Psychology. Houghton Mifflin Company, Boston.
Chase, S.I.
1992. "Why is the Sky Blue."
http://math.ucr.edu/home/baez/physics/blue_sky.html
(April 10, 2001)
Meinel, A. Sunsets. 1983. Twilights and Evening Skies. Cambridge University Press. New York.
Tilley, R. 2000.
Colour and the Optical Properties of Materials. John Wiley and
Sons,LTD,
England.
Wheadon, R.A.
1968. Principles of Light and Optics. Longmans, Green and Co
LTD,
Great Britian.