Arg. Saesneg gwreiddiol = Original English ed.: [Oxford]: Heinemann English Language Teaching, 1991.
Addasiad Cymraeg gan = Welsh adaptation by: Marian Beech Hughes.
Tric y siop lyfrau by John Escott. ISBN 1856444066. Published by Y Ganolfan Astudiaethau Addysg in 1999. Publication and catalogue information, links to buy online and reader comments.