Ling, P. (1995). Thoughts for effective living. Heinemann Asia.
Cita Chicago (17th ed.)Ling, Peter. Thoughts for Effective Living. Singapore: Heinemann Asia, 1995.
Cita MLA (9th ed.)Ling, Peter. Thoughts for Effective Living. Heinemann Asia, 1995.
Atenció: Aquestes cites poden no estar 100% correctes.