ScienceScope SCIENCESCOPE See allHide authors and affiliations Science 13 Jan 1995:Vol. 267, Issue 5195, pp. 163DOI: 10.1126/science.267.5195.163 Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears below.
Science Vol 267, Issue 519513 January 1995 Table of Contents Print Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)
