Peter, D. L. (1969). The Peter Principle: Why Things always go Wrong. Penguin.
Lua i Stíl Chicago (17ú heag.)Peter, Dr. Laurence. The Peter Principle: Why Things Always Go Wrong. Penguin, 1969.
Lua MLA (9ú heag.)Peter, Dr. Laurence. The Peter Principle: Why Things Always Go Wrong. Penguin, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.