Lidwell, W., & Holden, K. (2003). Universal principles and design. Rockport Publishers.
Chicago Style (17th ed.) ZitazioaLidwell, Wiliiam, eta Kritina Holden. Universal Principles and Design. Beverly, Massachusetts: Rockport Publishers, 2003.
MLA (9th ed.) ZitazioaLidwell, Wiliiam, eta Kritina Holden. Universal Principles and Design. Rockport Publishers, 2003.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.