Arg. Saesneg gwreiddiol = Original English ed.: Llundain: Collins Educational, 1993, 1995.
Yn cynnwys mynegai = Includes index.
Defnyddio egni, oed 7-12 : canllaw athrawon. ISBN 1855963655. Published by Gwasg y Dref Wen in 1998. Publication and catalogue information, links to buy online and reader comments.