Humble, J. (1967). Improving business result. Mc Graw Hill.
Cita Chicago (17th ed.)Humble, John. Improving Business Result. London: Mc Graw Hill, 1967.
Cita MLA (9th ed.)Humble, John. Improving Business Result. Mc Graw Hill, 1967.
Atenció: Aquestes cites poden no estar 100% correctes.