Arg. Saesneg gwreiddiol = Original English ed.: London: Piccadilly Press, 1991.
Addasiad Cymraeg gan = Welsh adaptation by: Brenda Wyn Jones.
Mêts o hyd by Terrance Dicks. ISBN 1859025285. Published by Gwasg Gomer in 1998. Publication and catalogue information, links to buy online and reader comments.