http://www.davincilife.com/biography1.html
http://legacy.mos.org/leonardo/bio.html
http://www.universalleonardo.org
http://legacy.mos.org/leonardo/scientist.html
http://www.zmescience.com/science/geology/5-things-leonardo-da-vinci-did-to-change-the-world/
http://www.bnl.gov/bera/activities/globe/leonardo_da_vinci.htm
http://library.thinkquest.org/J0112189/inventions_of_leonardo_davinci.htm
http://legacy.mos.org/leonardo/bio.html
http://www.universalleonardo.org
http://legacy.mos.org/leonardo/scientist.html
http://www.zmescience.com/science/geology/5-things-leonardo-da-vinci-did-to-change-the-world/
http://www.bnl.gov/bera/activities/globe/leonardo_da_vinci.htm
http://library.thinkquest.org/J0112189/inventions_of_leonardo_davinci.htm