Arg. Saesneg gwreiddiol = Original English ed.: Cambridge: Cambridge University Press, 1996.
Addasiad Cymraeg gan = Welsh adaptation by: Trosol Cyf.
Mathemateg pen 5 by Anita Straker. ISBN 1860853056. Published by Uned Iaith Genedlaethol Cymru in 1998. Publication and catalogue information, links to buy online and reader comments.