Impossible transforms are inexpressible
How I learned to Stop Worrying and Love Quaternions
Wikipedia: Conersion between quaternions and Euler angles
Wikipedia: Quaternions and spatial rotation
USE OF QUATERNIONS IN FLIGHT MECHANICS
NPSNET: FLIGHT SIMULATION DYNAMIC MODELING USING QUATERNIONS
W3C DeviceOrientation Event Specification
Practical Application and Usage of the W3C Device Orientation API
3D Game Engine Programming: Understanding Quaternions
@BrettHoutz paper on Quaternions