Document Type
Article
Publication Date
2001
Recommended Citation
Previously published in Proceedings of the National Academy of Sciences of the United States of America, 2001, volume 98, pp. 7265-7270 www.pnas.org
Article
2001
Previously published in Proceedings of the National Academy of Sciences of the United States of America, 2001, volume 98, pp. 7265-7270 www.pnas.org