Arg. Saesneg gwreiddiol = Original English ed.: Harlow: Longman Group, 1994.
Addasiad Cymraeg gan = Welsh adaptation by: Greville James.
Tair stori by Rob Childs. ISBN 186085334X. Published by Uned Iaith Genedlaethol Cymru in 1998. Publication and catalogue information, links to buy online and reader comments.