fixes pull #1371

free-programming-books.md

@@ -255,6 +255,7 @@ Original Source: [Free Programming books](http://stackoverflow.com/revisions/392
 * [Algorithms and Data-Structures](http://www.ethoberon.ethz.ch/WirthPubl/AD.pdf) (PDF)
 * [Algorithms Course Materials](http://compgeom.cs.uiuc.edu/~jeffe/teaching/algorithms/) - Jeff Erickson
 * [Analysis and Design of Algorithms](http://www.cse.iitd.ernet.in/~ssen/csl356/admin356.html) - Sandeep Sen, IIT Delhi
+* [Animated Algorithm and Data Structure Visualization](http://visualgo.net/) (Resource)
 * [Binary Trees](http://cslibrary.stanford.edu/110/BinaryTrees.pdf) (PDF)
 * [Clever Algorithms](http://www.cleveralgorithms.com/nature-inspired/index.html)
 * [Data Structures](http://www.cse.iitd.ernet.in/~suban/cs130/index.html) - Prof. Subhashis Banerjee, IIT Delhi