1. D. Bonatsos, N. Karoussos, C. Daskaloyannis, S. B. Drenska, N. Minkov, P. P. Raychev, R. P. Roussev, and J. Maruani: “Symmetries in nuclei, molecules and atomic clusters”, XHIth International School on Nuclear Physics, Neutron Physics and Nuclear Energy ( Varna, Bulgaria, September 1999 ).
2. The Encyclopedia Britannica (CD ROM 2000 Deluxe Edition & www pages).
3. Pythagoras and the Pythagoreans
http://www.math.tamu.edu
/-don.allen/historv/pvthag/pythag.hto
4. Pascal’s triangle
http://mathfonm.org
/dr.math/faq/faq.pascal.triangle.html
5. Midhat J. Gazale, Gnomon: From Pharaohs to Fractals, Princeton University Press, 1999, 259 pages.