The document provides references to various websites about volcanoes and volcanic activity. Specifically, it lists websites that contain information on lava flowing and sinking to the Earth's core, how far lava can travel when erupted, the eruption process of volcanoes generally, and tectonic plate movement which can cause volcanic activity.

49. REFERENCES
 http://www.youtube.com/watch?v=OowFvnlWI90
 http://guykeulemans.com/2010/03/dumb-probes-nuclear-fuel-sinking-to-the-centre-of-the-earth-melting-
rock-and-iron.html
 http://volcanology.geol.ucsb.edu/erupt.htm
 http://measure.igpp.ucla.edu/GK12-SEE-
LA/Lesson_Files_08/Brittany_Enzmann/How_Far_Lava_Lesson_BEnzmann.htm
 http://rmtc.fsdb.k12.fl.us/content/volcanoes.html
 http://sd71.bc.ca/sd71/school/courtmid/2004_student_web/7_3/B_chris/index.htm
 http://www.youtube.com/watch?v=OowFvnlWI90
 www.weatherwizkids.com/weather-volcano.htm
 http://www.thecityedition.com/Pages/Archive/2010/Upheaval_Page2.html
 http://www.geography-site.co.uk/pages/physical/earth/tect.html
 www.kids.discovery.com/games/build-play/volcano-explorer