The Colour Pencil By Gopal Nandurkar and Rahul Deshpande Book has a wide variety of subjects covering typical pastel techniques like stippling, cross-hatching, blending and many more.
The Acrylic Explorations By Rahul Deshpande Book includes 12 techniques, 6 step-by-step demonstrations and a gallery with a variety of subjects and approaches which shows the versatility of this medium.