"Crust (geology)" November 21st, 2011 Wikipedia, the Free Encyclopedia
<http://en.wikipedia.org/wiki/Crust_(geology)>
Pictures:
"What is the Temperature of the Earth’s Crust?" Universe Today December 15th, 2011 <http://www.universetoday.com/wp-content/uploads/2008/10/earth_interior.jpg>
Videos:
"Layers of the Earth ( High Definition )" You Tube November 21st, 2011 <http://www.youtube.com/watch?v=ukqe_6L9V54&feature=related>