Addasiad Cymraeg gan = Welsh adaptation by : Gwen Angharad Jones a Dylan Williams.
Argraffiad Saesneg gwreiddiol = Original English edition : London : Andersen Press, 2003.
Addewid y penbwl by Jeanne Willis. ISBN 1902416864. Published by Cymdeithas Lyfrau Ceredigion in 2003. Publication and catalogue information, links to buy online and reader comments.