APA (7th ed.) Citation

Campbell, R., Operamolla, A., & Cleary, M. (2010). The time capsule. Helbling Languages.

Chicago Style (17th ed.) Citation

Campbell, Robert, Arianna Operamolla, and Maria Cleary. The Time Capsule. Londres: Helbling Languages, 2010.

MLA (9th ed.) Citation

Campbell, Robert, et al. The Time Capsule. Helbling Languages, 2010.