Arg. Saesneg gwreiddiol = Original English ed.: Cambridge : Cambridge University Press, 1993.
Addasiad Cymraeg: Uned Iaith Genedlaethol Cymru, CBAC = Welsh adaptation: National Language Unit of Wales, WJEC.
Darnau cymdeithas. Llyfr adnoddau'r athro : yn cynnwys dalennau i'w llungopïo by David Lambert. ISBN 1860851002. Published by Uned Iaith Genedlaethol Cymru CBAC in 1996. Publication and catalogue information, links to buy online and reader comments.