Argraffiad Saesneg gwreiddiol = Original English edition : London : Usborne Publishing, 2002.
Addasiad Cymraeg gan = Welsh adaptation by : Emily Huws.
Clock book.
Cloc Cae Berllan by Heather Amery. ISBN 1843232421. Published by Gwasg Gomer in 2003. Publication and catalogue information, links to buy online and reader comments.