References
AQA
- Glands, page 61, GCSE Combined Science; The Revision Guide, CGP, AQA
- Glands, page 73, GCSE Biology; The Revision Guide, CGP, AQA
- Glands, pages 12-13, GCSE Combined Science Trilogy 2, Hodder, AQA
- Glands, pages 67, 181, 182, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Glands, pages 73, 207, 208, GCSE Biology, CGP, AQA