1. Gestural design tools: prototypes, experiments and scenarios;Hummels,2000
2. What architects see in their sketches: implications for design tools;Suwa,1996
3. Sketching for design and design of sketches;Tversky,2003
4. The reflective practitioner. How professionals think in action;Schön,1983
5. Konstruktionslehre. Grundlagen erfolgreicher Produktentwicklung. Methoden und Anwendung;Pahl,2005