Cita APA (7th ed.)

Write better, speak better. Reader's Digest Association.

Cita Chicago (17th ed.)

Write Better, Speak Better. Pleasantville, N.Y.: Reader's Digest Association.

Cita MLA (9th ed.)

Write Better, Speak Better. Reader's Digest Association.

Atenció: Aquestes cites poden no estar 100% correctes.