APA

Gardner J. W., . (1990). John W. Gardner on leadership. New York: The Free Press.

Chicago

Gardner John W, . 1990. John W. Gardner on leadership. New York: The Free Press.

Harvard

Gardner J. W., . (1990). John W. Gardner on leadership. New York: The Free Press.

MLA

Gardner John W, . John W. Gardner on leadership. New York: The Free Press. 1990.