Mathemateg.
Sherlock, A. J.(Alan Jeffrey)
Jones, Lynwen Rees.
University College of Wales (Aberystwyth, Wales).Centre for Educational Studies.
Aberystwyth : Canolfan Astudiaethau Addysg,
1994.
In spiral binding.
Arg. Saesneg gwreiddiol = Original English ed: 1987
Teitl clawr = Cover title
Mathematics