Cita APA (7a ed.)

Dean, M., Sikorzynska, A., Mower, D., & Harris, M. (2002). Opportunities: Intermediate. Longman.

Cita Chicago Style (17a ed.)

Dean, Michael, Anna Sikorzynska, David Mower, y Michael Harris. Opportunities: Intermediate. England: Longman, 2002.

Cita MLA (9a ed.)

Dean, Michael, et al. Opportunities: Intermediate. Longman, 2002.