1. An animation of the evolution of the Phoenician character set can be found at http://www.wam.umd.edu/~rfradkin/latin.html.
2. A. N. Whitehead An Introduction to Mathematics (Henry Holt New York 1911).
3. Science 's STKE (http://stke.sciencemag.org/).
4. AfCS Web site http://www.signaling-gateway.org/.
5. Poster from NIH Digital Biology meeting on the University of Washington Cell Systems Initiative (UW/CSI) Web site http://www.csi.washington.edu/pub/modeling/pix/BISTICPoster2003sm.jpg.