Arg. Saesneg gwreiddiol = Original English ed.: [London]: Collins Educational, 1988.
Addasiad Cymraeg gan = Welsh adaptation by: Rhiannon Parry.
Llinynnau. llyfr 4 by John Foster. ISBN 1856443272. Published by Canolfan Astudiaethau Addysg in 1998. Publication and catalogue information, links to buy online and reader comments.