Eissen, K., & Steur, R. Sketching: Drawing techniques for product designers.
Cita Chicago (17th ed.)Eissen, Koos, i Roselien Steur. Sketching: Drawing Techniques for Product Designers.
Cita MLA (8th ed.)Eissen, Koos, i Roselien Steur. Sketching: Drawing Techniques for Product Designers.
Atenció: Aquestes cites poden no estar 100% correctes.