De Bono, E. (1999). Simplicity. Penguin Books.
Lua i Stíl Chicago (17ú heag.)De Bono, Edward. Simplicity. London: Penguin Books, 1999.
Lua MLA (9ú heag.)De Bono, Edward. Simplicity. Penguin Books, 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.