Cita APA (7a ed.)

Sayer, M., Dellar, H., & Walkley, A. (2016). Outcome: Intermediate Teacher's Book. National Geographic Learning; Cengage Learning.

Cita Chicago Style (17a ed.)

Sayer, Mike, Hugh Dellar, y Andrew Walkley. Outcome: Intermediate Teacher's Book. United Kingdom: National Geographic Learning; Cengage Learning, 2016.

Cita MLA (9a ed.)

Sayer, Mike, et al. Outcome: Intermediate Teacher's Book. National Geographic Learning; Cengage Learning, 2016.