Addasiad Cymraeg gan = Welsh adaptation by : Colin Isaac.
Argraffiad Saesneg gwreiddiol = Original English edition : Kirkby-in-Furness : Coordination Group Publications, 2001.
Bioleg : y llyfr gwaith haen uwch : gydag atebion. ISBN 185644578X. Published by Y Ganolfan Astudiaethau Addysg in 2001. Publication and catalogue information, links to buy online and reader comments.