Peter, L. J. (2007). The Peter Principle. W.W. Norton & Company.
Lua i Stíl Chicago (17ú heag.)Peter, Laurence J. The Peter Principle. New York: W.W. Norton & Company, 2007.
Lua MLA (9ú heag.)Peter, Laurence J. The Peter Principle. W.W. Norton & Company, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.