diff --git a/free-programming-books-es.md b/free-programming-books-es.md
index cd94a68f..b2b0b891 100644
--- a/free-programming-books-es.md
+++ b/free-programming-books-es.md
@@ -121,6 +121,7 @@
 
 ####Node.js
 
+* [Introducción a Node.js a través de Koans](http://nodejskoans.com/)
 * [El Libro para Principiantes en Node.js](http://www.nodebeginner.org/index-es.html)
 
 ###LaTeX