Overarching Problems » American Scientist
How the keystone “motif” is used in contexts other than construction (e.g. Penn state logo)
http://www.americanscientist.org/issues/pub/overarching-problems November-December 2012
Volume 100, Number 6
Page: 458
DOI: 10.1511/2012.99.458
Overarching Problems
Keystones, whether employed to complete an arch or as a metaphor, require care in their use
Henry Petroski