Nunan, D., & David Nunan. (1999). Speak out. Singapore: International Thomson Asia ELT.
Chicago Style CitationNunan, David, i David Nunan. Speak Out. Singapore: International Thomson Asia ELT, 1999.
Cita MLANunan, David, i David Nunan. Speak Out. Singapore: International Thomson Asia ELT, 1999.
Atenció: Aquestes cites poden no estar 100% correctes.