APA (7th ed.) Citation

Dummett, P., Stephenson, H., & Lansford, L. (2017). Keynote proficient. National Geographic Learning.

Chicago Style (17th ed.) Citation

Dummett, Paul, Helen Stephenson, and Lewis Lansford. Keynote Proficient. Andover, Hampshire: National Geographic Learning, 2017.

MLA (9th ed.) Citation

Dummett, Paul, et al. Keynote Proficient. National Geographic Learning, 2017.