Lua APA (7ú heag.)
Friedel, R. D. (2007). A culture of improvement: Technology and the Western millennium. MIT Press.
Lua i Stíl Chicago (17ú heag.)
Friedel, Robert D. A Culture of Improvement: Technology and the Western Millennium. Cambridge, MA: MIT Press, 2007.
Lua MLA (9ú heag.)
Friedel, Robert D. A Culture of Improvement: Technology and the Western Millennium. MIT Press, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.