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+_Think Complexity_ is an introduction to complexity science
+using Python.  The premise of this book (and the other books in the _Think X_ series) is that if 
+you know how to program, you can use that skill to learn other things.  
+
+The first edition is published by [O'Reilly Media](http://shop.oreilly.com/product/0636920022480.do).
+You can also [order it from Amazon](http://amzn.to/2nwkoZS).
+
+The second edition is a work in progress, available in PDF from
+[Green Tea Press](http://greenteapress.com/wp/think-complexity-2e/).
+
+The book is under a Creative Commons license: 
+[Attribution-NonCommercial-ShareAlike 3.0 Unported](http://creativecommons.org/licenses/by-nc-sa/3.0).
+The code is under the [GNU GPLv3](http://www.gnu.org/licenses/gpl.html).
+
+Other Free Books by Allen Downey are available from [Green Tea Press](http://greenteapress.com/wp/).
+
+
+### Tutorial
+
+I offer a half-day tutorial based on material from _Think Complexity_.
+[Information about the tutorial is here](http://allendowney.github.io/ThinkComplexity2/tutorial).
+