Richards, J. C., Bycina, D., Wisniewska, I., & Kocienda, G. (2006). Person to person communicative speaking and listening skills. Teacherïs book 2 (3a. ed.). Oxford University Press.

Richards, Jack C., David Bycina, Ingrid Wisniewska, and Genevieve Kocienda. Person to Person Communicative Speaking and Listening Skills. Teacherïs Book 2. 3a. ed. Nueva York: Oxford University Press, 2006.

Richards, Jack C., et al. Person to Person Communicative Speaking and Listening Skills. Teacherïs Book 2. 3a. ed. Oxford University Press, 2006.