101 Things You Didn't Know About Da Vinci Page 20
by Shana Priwer
Da Vinci, Leonardo. The Notebooks of Leonardo Da Vinci, Complete, Edition 9. Translator Jean Paul Richter, 1888. Oxford, Mississippi: Project Gutenberg, 2001, 2002 by Michael S. Hart: www.gutenberg.org/dirs/etext04/7ldvc09.txt (accessed October 22, 2004).
Da Vinci, Leonardo. The Notebooks of Leonardo Da Vinci, Complete, Edition 10. Translator Jean Paul Richter, 1888. Oxford, Mississippi: Project Gutenberg, 2001, 2002 by Michael S. Hart: www.gutenberg.org/dirs/etext04/8ldvc10.txt (accessed October 22, 2004).
Freud, Sigmund. Leonardo da Vinci and a Memory of His Childhood. New York: W.W. Norton ' Company, reissue edition, 1999.