Arg. Saesneg gwreiddiol = Original English ed.: [London]: Collins Educational, 1988.
Addasiad Cymraeg gan = Welsh adaptation by: Colin Isaac.
Llinynnau. llyfr 5 by John Foster. ISBN 1856443280. Published by Y Ganolfan Astudiaethau Addysg in 1998. Publication and catalogue information, links to buy online and reader comments.