Concept
Version 13
Created by Boundless
Significant Figures
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"All sizes | significant figures | Flickr - Photo Sharing!."
http://www.flickr.com/photos/conskeptical/361554984/sizes/m/
Flickr
CC BY-SA.