1. Askew, M., Brown. M., Rhodes, V.. Johnson. D & Wiliam, D. (1997) Effective Teachers of Numeracy, London: King’s College.
2. Benn. R. (1997) Adults Count Too: mathematics for empowerment, Leicester: National Institute of Adult Continuing Education
3. Brousseau, G. & Otte, M. (1991) ‘The fragility of knowledge’. In A.J. Bishop, S. Mellin-Olsen & J. van Dormolen (Eds.) Mathematical Knowledge: Its Growth through Teaching. Dordrecht: Kluwer.
4. Byers, V. (1980) ‘What does it mean to understand mathematics?’ International Journal of Mathematical Education in Science and Technology, 11(1), 1–10.
5. Cooper; B. (1990) ‘PGCE student and investigational approaches in secondary maths’. Research Papers in Education, 5(2), 127–151