Another good one: Fast Sketching Techniques by David Rankin https://www.thriftbooks.com/w/fast-sketching-techniques-capture-the-fundamental-essence-of-elusive-

Another good one: Fast Sketching Techniques by David Rankin https://www.thriftbooks.com/w/fast-sketching-techniques-capture-the-fundamental-essence-of-elusive-subjects_david-rankin/37792433/ https://www.thriftbooks.com/w/fast-sketching-techniques-capt...