Citazione Stile APA (7a Edizione)

Clemens, R., Crabbe, M., & Moule, L. (2009). OCR GCSE Geography - specification A (1st publ.). Heinemann.

Citazione stile Chigago Style (17a edizione)

Clemens, Rob, Martin Crabbe, e Lesley Moule. OCR GCSE Geography - Specification A. 1st publ. Harlow: Heinemann, 2009.

Citatione MLA (9a ed.)

Clemens, Rob, et al. OCR GCSE Geography - Specification A. 1st publ. Heinemann, 2009.