Letters Response See allHide authors and affiliations Science 09 Aug 1991:Vol. 253, Issue 5020, pp. 608-609DOI: 10.1126/science.253.5020.608-b ALAN J. KRUPNICKFind this author on Google Scholar Find this author on PubMed Search for this author on this site PAUL R. PORTNEYFind this author on Google Scholar Find this author on PubMed Search for this author on this site Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears below.
Science Vol 253, Issue 502009 August 1991 Table of Contents Print Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)