Drucker, P. F. (1967). The effective executive. Heinemann.
Cita Chicago (17th ed.)Drucker, Peter F. The Effective Executive. London: Heinemann, 1967.
Cita MLA (8th ed.)Drucker, Peter F. The Effective Executive. Heinemann, 1967.
Atenció: Aquestes cites poden no estar 100% correctes.