Argraffiad Saesneg gwreiddiol = Original English edition : London : Orion Publishing, 2001.
Addasiad Cymraeg gan = Welsh adaptation by : Elin Meek.
Henri Helynt yn dial by Francesca Simon. ISBN 9781845211622. Published by Y Ganolfan Astudiaethau Addysg in 2007. Publication and catalogue information, links to buy online and reader comments.