Kouzes, J. M., & Posner, B. Z. (2007). The leadership challenge (4th ed.). Jossey-Bass.
Lua i Stíl Chicago (17ú heag.)Kouzes, James M., agus Barry Z. Posner. The Leadership Challenge. 4th ed. San Francisco, USA: Jossey-Bass, 2007.
Lua MLA (9ú heag.)Kouzes, James M., agus Barry Z. Posner. The Leadership Challenge. 4th ed. Jossey-Bass, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.