Association AffairsAAAS Meeting AAAS Council Meeting See allHide authors and affiliations Science 05 Oct 1990:Vol. 250, Issue 4977, pp. 93DOI: 10.1126/science.250.4977.93 Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears below.
Science Vol 250, Issue 497705 October 1990 Table of Contents Print Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)
