Argraffiad Saesneg gwreiddiol = Original English edition : London : Egmont Children's Books, 2003.
Addasiad Cymraeg gan = Welsh adaptation by : Elin Meek.
Siriol Llywelyn a'r salwch chwyrlio erchyll by David Sutherland. ISBN 1855966794. Published by Gwasg y Dref Wen in 2005. Publication and catalogue information, links to buy online and reader comments.