Addasiad Cymraeg gan = Welsh adaptation by: Delyth Ifan.
Rhaglen gyfoethogi mathemateg. Llyfr ymarfer : blwyddyn 11 (modwl 3). ISBN 186085415X. Published by Uned Iaith Genedlaethol Cymru CBAC in 1999. Publication and catalogue information, links to buy online and reader comments.