A MUST HAVE: Buy Real Time Rendering, 3rd edition! (if you haven't already) It's from 2008 but the content is still extremely useful and will teach you the "fundamentals" you're looking for .
You can also check out "Mathematics for 3D Game Programming and Computer Graphics, Third Edition" or "3D Math Premier for Graphics and Game Development".
Then you have the ShaderX/GPU Pro series that contain a wide range of techniques that might be useful to you (check the TOC before buying).
Also read papers/presentations from SIGGRAPH and GDC for free and useful techniques, like this ones