APA (7th ed.) Citation

Widdowson, J., Smith, J., & Knill, R. (2001). GCSE geography in focus (1. publ.). Murray.

Chicago Style (17th ed.) Citation

Widdowson, John, John Smith, and Roger Knill. GCSE Geography in Focus. 1. publ. London: Murray, 2001.

MLA (9th ed.) Citation

Widdowson, John, et al. GCSE Geography in Focus. 1. publ. Murray, 2001.