Arg.Saesneg gwreiddiol = Original English ed.: Cheltenham: Stanley Thornes, 1995.
Yn cynnwys mynegai = Includes index.
Addasiad Cymraeg gan = Welsh adaptation by: Ceri Williams, John Williams, Sandra Williams a Delyth Ifan.
Gwefr gwyddoniaeth by Keith Johnson. ISBN 1856443736. Published by Y Ganolfan Astudiaethau Addysg in 1999. Publication and catalogue information, links to buy online and reader comments.