APA (7th ed.) Citation

Dellar, H., & Walkley, A. (2017). Outcomes: Advanced Student's book. National Geographic Learning; Cengage Learning.

Chicago Style (17th ed.) Citation

Dellar, Hugh, and Andrew Walkley. Outcomes: Advanced Student's Book. United Kingdom: National Geographic Learning; Cengage Learning, 2017.

MLA (9th ed.) Citation

Dellar, Hugh, and Andrew Walkley. Outcomes: Advanced Student's Book. National Geographic Learning; Cengage Learning, 2017.