Products & Materials PRODUCTS and MATERIALS Science 08 Nov 1974:Vol. 186, Issue 4163, pp. 557-558DOI: 10.1126/science.186.4163.557 Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears above.
Science Vol 186, Issue 416308 November 1974 Table of Contents Print Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)
