Argrafiad Saesneg gwreiddiol = Original English edition : Oxford : Rigby, 1999.
Addasiad Cymraeg gan = Welsh adaptation by : Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru.
Ffocws rhifedd 3 : problem yr wythnos by John Spooner. ISBN 0948469749. Published by Gwasg Taf in 2001. Publication and catalogue information, links to buy online and reader comments.