Cita APA (7a ed.)

Ashworth, J., & Clark, J. (1999). I-spy: Course book 1. Oxford University.

Cita Chicago Style (17a ed.)

Ashworth, Julie, y John Clark. I-spy: Course Book 1. Oxford: Oxford University, 1999.

Cita MLA (8a ed.)

Ashworth, Julie, y John Clark. I-spy: Course Book 1. Oxford University, 1999.