Argraffiad Saesneg gwreiddiol = Original English edition: London : Orchard Books, 2000.
Addasiad Cymraeg gan = Welsh adaptation by: Elin Meek.
Pan fyddi di'n cysgu by John Butler. ISBN 185902856X. Published by Gwasg Gomer in 2000. Publication and catalogue information, links to buy online and reader comments.