APA (7th ed.) Citation

Downie, M., Gray, D., & Jiménez, J. M. (1993). Freeform: Student's book 1. Santillana.

Chicago Style (17th ed.) Citation

Downie, Michael, David Gray, and Juan Manuel Jiménez. Freeform: Student's Book 1. London: Santillana, 1993.

MLA (9th ed.) Citation

Downie, Michael, et al. Freeform: Student's Book 1. Santillana, 1993.