Mohasboon - System Dynamics History. May 17, 2003. Mohasboon Global Solutions. 
     3 July  2003. <http://mohasboon.com/SDHist.htm>

Waters Foundation. Waters Foundation K-12 Educational Partnership. 2003. Waters Foundation.
     3 July 2003. <http://watersfoundation.org/>

Ventana Systems, Inc. Vensim® History. 2003. Ventana Systems, Inc. 3 July 2003.
     <http://www.vensim.com/history.html>

All of our images were produced from scratch or from screenshots from Stella.

Besides the History section, our content came from James.