http://youtu.be/IcpvklHTF6I

http://www.4shared.com/office/7F9dAAAQ/Um_pouco_da_Historia_da_Trigon.html

http://www.4shared.com/document/Qm1P5PyJ/Helen_screencast.html

http://www.4shared.com/mp3/cvOc72-Z/A_Linguagem_dos_Nmeros.html