Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

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

Citatione MLA (9a ed.)

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