Addasiad Cymraeg gan = Welsh adaptation by : Aled Davies.
OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
Diwrnod blin : Tomos yn dysgu dweud mae'n ddrwg gen i by Stephanie Jeffs. ISBN 1859944027. Published by Cyhoeddiadau'r Gair in 2002. Publication and catalogue information, links to buy online and reader comments.
