Addasiad Cymraeg gan = Welsh adaptation by : Bethan Clement.
Argraffiad Saesneg gwreiddiol = Original English edition : New Zealand : Nelson Australia, 1993.
Pws a'r adar by Beverley Randell. ISBN 1856447995. Published by Canolfan Astudiaethau Addysg in 2003. Publication and catalogue information, links to buy online and reader comments.