Morales Cordero, E. M. 1., Gómez Atencio, S. 1., Ramírez Castro, M., Retana Mora, C., Sierra Santibañez, V., Arroyo Molina, S. A. 1., . . . Atencio Brunelli, E. (2013). Teen English Class 9: Student's book (1. edition.). Costa Rica: Santillana S.A..

Morales Cordero, Elsa María 1955-, Sergio 1971- Gómez Atencio, Monserrat Ramírez Castro, Carolina Retana Mora, Vianey Sierra Santibañez, Sergio Antonio 1976- Arroyo Molina, Waleska Sucre Zabala, and Elsa Atencio Brunelli. Teen English Class 9: Student's Book. 1. edition. Costa Rica: Santillana S.A., 2013.

Morales Cordero, Elsa María 1955-, et al. Teen English Class 9: Student's Book. 1. edition. Costa Rica: Santillana S.A., 2013.