APA (7th ed.) Citation

Open University Worldwide, Woolfe, H., Galloway, M., & Saunders, M. (2011). Worlds of english. Open University Worldwide.

Chicago Style (17th ed.) Citation

Open University Worldwide, Harvey Woolfe, Mark Galloway, and Michaela Saunders. Worlds of English. Milton Keynes, U.K: Open University Worldwide, 2011.

MLA (9th ed.) Citation

Open University Worldwide, et al. Worlds of English. Open University Worldwide, 2011.

Warning: These citations may not always be 100% accurate.