Original: “Social Network Analysis Visualization” by Martin Grandjean via Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Social_Network_Analysis_Visualization.png. License: Creative Commons Attribution-Share Alike 3.0 Unported, https://creativecommons.org/licenses/by-sa/3.0/deed.en. Modified by Terry Burkes for Teach Global Impact/ICSI. (License for mod: Attribution-ShareAlike 4.0 International, http://creativecommons.org/licenses/by-sa/4.0/.)