APA (7th ed.) Citation

Stephenson, H., Lansford, L., & Dummett, P. (2016). Keynote - upper intermediate: B2. National Geographic Learning.

Chicago Style (17th ed.) Citation

Stephenson, Helen, Lewis Lansford, and Paul Dummett. Keynote - Upper Intermediate: B2. Andover, Hampshire: National Geographic Learning, 2016.

MLA (9th ed.) Citation

Stephenson, Helen, et al. Keynote - Upper Intermediate: B2. National Geographic Learning, 2016.