Gaya APA

Posner, J, M, K, ;, B, Z. (1995). The leadership challenge: how to keep getting extraordinary things done in organizations . San Francisco: Jossey-Bass Publisher.

Gaya MLA

Posner, James, M, Kouzes, ;, Barry, Z. "The leadership challenge: how to keep getting extraordinary things done in organizations". San Francisco: Jossey-Bass Publisher, 1995. Text.