Merge pull request #113 from jeroendoggen/master

Added "Object-Oriented Reengineering Patterns" by Demeyer, Ducasse & Nie...

free-programming-books.md

@@ -228,6 +228,7 @@
 * [The Art of Computer Programming](http://www.cs.utsa.edu/~wagner/knuth/) (fascicles, mostly volume 4)
 * [Think Complexity](http://www.greenteapress.com/compmod/) - Allen B. Downey
 * [Introduction to High-Performance Scientific Computing](http://tacc-web.austin.utexas.edu/veijkhout/public_html/istc/istc.html) - Victor Eijkhout
+* [Object-Oriented Reengineering Patterns](http://win.ua.ac.be/~sdemey/) - Serge Demeyer, Stéphane Ducasse and Oscar Nierstrasz
 
 
 ####MOOC