1. editor. The Alhambra and Genaralife in focus. Granada: Edilux S.L; 2000.
2. Private communication from Daniel Grammatico (an authority and writer on Islamic history and art, recommended by the Alhambra museum); 2005. Email: dgrammatico@tmdigital.es.
3. Zur Lehre vom Lichtsinn. Wein: Gerald & Sohn; 1878. (Translation by Hurvich LM, Theory of the Light Sense, Harvard College, 1964.)
4. Instituto Geografico de Agostini, editors. Leonardo da Vinci. Rome: Instituto Geografico; 1964.
5. Understanding color. http://www.gpa.etsmtl.ca/cours/sys844/Documents/Document1.pdf