Twelve booklets in a folder in a plastic envelope.
Dyddiau pwysig by Cynllun y Cyngor Ysgolion, y Gymraeg fel Iaith Gyntaf yn yr Ysgol Gynradd. ISBN 0850883873. Published by Gwasg Gomer ar ran y Cyngor Ysgolion in 1977. Publication and catalogue information, links to buy online and reader comments.