Prashant Kumar. (2012). Product design: Creativity concepts and usability. PHI.
Chicago Style aipamenaPrashant Kumar. Product Design: Creativity Concepts and Usability. New Delhi: PHI, 2012.
MLA aipamenaPrashant Kumar. Product Design: Creativity Concepts and Usability. PHI, 2012.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.