Crizmac has a video with instruction guide and handout--"Whistle While You
Sculpt"-- Sells for $39.95 (catalog number 2400)
They also sell a paper back book - Clay Whistles: The Voice of Clay - by
Janet Moniot - sells for $11.95 (catalog number 2411)
(Crizmac Phone 1-800-913-8555 http://www.crizmac.com )
I have to confess, I only tried to make a whistle once and mine didn't
whistle.