Back to matchesWe found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleLetter to the editor.AuthorsBirks, L. S.PublicationXRS: X-ray Spectrometry, 1981, Vol 10, Issue 3, p152ISSN0049-8246Publication typeArticleDOI10.1002/xrs.1300100313