The present study complements the study on patents, patent applications and other literature on rare earth metals based permanent magnets by Frits Andriessen and Marten Terpstra, published by Elsevier Applied Science in 1989, and complements in part the book on Nd-Fe permanent magnets edited by LV. Mitchell, which was the result of a workshop organized by the Commission of the European Communities and held in Brussels on 25 October 1984. The difference between the content of the first book and that of the present study is that the first is more specifically directed to various kinds and...