diff --git a/free-programming-books.md b/free-programming-books.md
index ef34bf6a97448441c5eea19038f86f83e55aa1fe..0594971ec264ffd6d031620994c845e9bb301d54 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -1159,6 +1159,7 @@
 * [HTML5 Shoot 'em Up in an Afternoon](https://leanpub.com/html5shootemupinanafternoon/read) - Bryan Bibat
 * [Learn CSS Layout](http://learnlayout.com)
 * [Learn CSS Layout the pedantic way](http://book.mixu.net/css/)
+* [MaintainableCSS](http://maintainablecss.com)
 * [Pro HTML5 Programming]( http://apress.jensimmons.com/v5/pro-html5-programming/ch0.html)
 * [Scalable and Modular Architecture for CSS](https://smacss.com) - Jonathan Snook
 * [Web Audio API](http://chimera.labs.oreilly.com/books/1234000001552) - Boris Smus