Arg. Saesneg gwreiddiol = Original English ed.: Llundain: Picadilly Press, 1998.
Addasiad Cymraeg gan = Welsh adaptation by: Hedd a Non ap Emlyn.
Ryan a'i helfa drysor by Lisa Stubbs. ISBN 1855963728. Published by Gwasg y Dref Wen in 1998. Publication and catalogue information, links to buy online and reader comments.