'Iaith nas arferir, iaith i farw yw' : ymgyrch dros yr iaith Gymraeg rhwng y ddau ryfel byd by Marion Löffler. ISBN 0947531343. Published by Canolfan Uwchefrydiau Cymreig a Cheltaidd Prifysgol Cymru in 1995. Publication and catalogue information, links to buy online and reader comments.