Arg. Saesneg gwreiddiol = Original English ed.: Llundain: Egmont Children's Books, 1997.
Addasiad Cymraeg gan = Welsh adaptation by: Luned Whelan.
Dwi'n hapus pan - by Mary Murphy. ISBN 0852842392. Published by Hughes a'i Fab in 1999. Publication and catalogue information, links to buy online and reader comments.