Lidwell William,Holden K. (2010). Universal Principles of Design. Rock Port.
Chicago Style aipamenaLidwell William,Holden K. Universal Principles of Design. USA: Rock Port, 2010.
MLA aipamenaLidwell William,Holden K. Universal Principles of Design. Rock Port, 2010.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.