Robertson, S., & Bertling, T. How to draw: Drawing and sketching objects and environments from your imagination.
Citazione stile Chigago Style (17a edizione)Robertson, Scott, e Thomas Bertling. How to Draw: Drawing and Sketching Objects and Environments from Your Imagination.
Citatione MLA (8a ed.)Robertson, Scott, e Thomas Bertling. How to Draw: Drawing and Sketching Objects and Environments from Your Imagination.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.