Ulrich, K. (2008). Product design and development fourth edition. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Ulrich, Karl. Product Design and Development Fourth Edition. McGraw-Hill, 2008.
Lua MLA (8ú heag.)Ulrich, Karl. Product Design and Development Fourth Edition. McGraw-Hill, 2008.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.