Covey, S. R. . .. (1998). Principle centred leadership. Simon and schuster.
Chicago Edition CitationCovey, Stephen R. Principle Centred Leadership. London: Simon and schuster, 1998.
Cita MLACovey, Stephen R. Principle Centred Leadership. Simon and schuster, 1998.
Atenció: Aquestes cites poden no estar 100% correctes.