Maxwell, J. C., & Stephen R. Covey. (2007). The 21 irrefutable laws of leadership: Follow them and people will follow you (10th ed.). Thomas Nelson.
Lua i Stíl Chicago (17ú heag.)Maxwell, John C., agus Stephen R. Covey. The 21 Irrefutable Laws of Leadership: Follow Them and People Will Follow You. 10th ed. Tennessee, Mexico: Thomas Nelson, 2007.
Lua MLA (9ú heag.)Maxwell, John C., agus Stephen R. Covey. The 21 Irrefutable Laws of Leadership: Follow Them and People Will Follow You. 10th ed. Thomas Nelson, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.