The Exceptionally Simple Theory of Sketching: Easy to Follow Tips and Tricks to Make your Sketches Look Beautiful

How to Sketch: A Beginner's Guide to Sketching Techniques, Including Step By Step Exercises, Tips and Tricks

Drawing for Product Designers (Portfolio Skills: Product Design)

Sketching: The Basics (2nd printing)

Drawing Ideas: A Hand-Drawn Approach for Better Design

Pen and Ink Drawing: A Simple Guide

Sketching (12th printing): Drawing Techniques for Product Designers

How to Draw: drawing and sketching objects and environments from your imagination

Freehand Figure Drawing for Illustrators: Mastering the Art of Drawing from Memory

5-Minute Sketching -- People: Super-quick Techniques for Amazing Drawings

The Industrial Design Reference & Specification Book: Everything Industrial Designers Need to Know Every Day