1. - Babbit, Edwin (1878) “The Principles of Light and Color” East Orange NJ.
2. - Babbit Edwin (1967) “The Principles of Light and Color” The Citadel Press.
3. - Birren, Faber (1969, 1982) “Light, Color & Environment” Revised Edition, New York; Van-Nostrand Reinhold Company, Inc.
4. - Graham, Helen (1998) “Discover Color Therapy” A history of color therapy, amazon. com.
5. - Kandinsky, Wassily (1914) “The Art of Spiritual Harmony” Boston: Houghton Mifflin Co.