Arg. Saesneg gwreiddiol = Original English ed.: London : A. & C. Black, 2004.
Cyfieithydd = Translator: Ffion Kervegant.
Trin data : gweithgareddau i ddysgu rhifedd. Blwyddyn 8 by Hilary Koll. ISBN 9781845212223. Published by Canolfan Astudiaethau Addysg in 2008. Publication and catalogue information, links to buy online and reader comments.