Arg. Saesneg gwreiddiol = Original English ed.: [London]; HarperCollins Publishers, 1998.
Addasiad Cymraeg gan = Welsh adaptation by: Gwynne Williams.
Balŵn by Jez Alborough. ISBN 185596340X. Published by Gwasg y Dref Wen in 1999. Publication and catalogue information, links to buy online and reader comments.