To learn more about the mysteries of the crystal skulls, visit these Web sites:

http://www.csicop.org/si/2006-04/nickell.html

http://www.archaeology.org/0805/etc/indy.html

http://www.mitchell-hedges.com/

http://www.world-mysteries.com/sar_6_1.htm

http://www.mendhak.com/80-the-13-crystal-skulls.aspx

http://www.unmuseum.org/cryskull.htm

http://en.wikipedia.org/wiki/Crystal_skull

http://science.howstuffworks.com/crystal-skull.htm

http://en.epochtimes.com/news/5-8-21/31477.html

http://www.slashfilm.com/2008/05/08/indiana-jones-4-27-new-photos-and-the-history-of-the-crystal-skulls