The Mobile Tongue
Loosen Your Jaw
The Open Throat
A Lip and Tongue Thing
The Sing Thing Explained - in video. Page 1 - Page 2 - Page 3
The breathing exercises (and breathing generally) are covered in exquisite detail separately:
Breathing, Breathing and alignment with Anya, Breathing Practice.
The right hand pane links to YouTube, you can download the videos from the left hand pane.