101 Textures in Graphite & Charcoal: Practical step-by-step drawing techniques for rendering a variety of surfaces & textures Paperback – Illustrated, January 9, 2018

101 Textures in Graphite & Charcoal: Practical step-by-step drawing techniques for rendering a variety of surfaces & textures

Drawing Dimension - Shading Techniques: A Shading Guide for Teachers and Students (How to Draw Cool Stuff)