Allwedd mathemateg TGAU :
Baker, David,1961-
Kervegant, Ffion.
University of Wales, Aberystwyth.Centre for Educational Studies.
Aberystwyth : Canolfan Astudiaethau Addysg,
2005.
Argraffiad Saesneg gwreiddiol = Original English edition: Cheltenham: Stanley Thornes, 1998.
Cyfieithwyd gan = Transalted by Ffion Kervegant.
Mathematics