Hi all!

I'm searching for a new book convering advanced shading techniques. I found the following books covering this topic:

Gpu Gems: Programming Techniques, Tips and Tricks for Real-Time Graphics
Direct3D Shaderx: Vertex & Pixel Shader Tips and Techniques
Shaderx2: Shader Programming Tips and Tricks with DirectX 9.0

What do you think about these books? Are they recommendable?

Thanks a lot