http://www.gustinceramics.com/sculpture/workshops/watershed1999/ines_amado/
http://www.schoolsupplies.co.nz/workshop/Projects/earth_fire_stone.html
http://home.t-online.de/home/Max.Braunweiler/epapiero.htm
http://www.umanitoba.ca/schools/art/ceramics/activity/pkiln00.html