diff --git a/free-programming-books-es.md b/free-programming-books-es.md
index ad3bc1b4..683e725c 100644
--- a/free-programming-books-es.md
+++ b/free-programming-books-es.md
@@ -86,6 +86,7 @@
 * [97 cosas que todo programador debería saber](http://97cosas.com/programador)
 * [El camino a un mejor programador](http://emanchado.github.io/camino-mejor-programador/)
 * [Videojuegos Multiplataforma con OpenFL](http://www.openflbook.com/)
+* [Programación de videojuegos SDL](http://www.albertogarcia.info/libros/sdl/%5Bebook%5DProgramacion%20de%20videojuegos%20con%20SDL.pdf) (PDF)
 
 
 #### Paradigmas de Programación
diff --git a/free-programming-books.md b/free-programming-books.md
index 0b291584..aec9d25e 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -698,6 +698,7 @@
 * [The Craft of Text Editing or A Cookbook for an Emacs](http://www.finseth.com/craft/) - Craig A. Finseth
 * [The New C Standard - An Annotated Reference](http://www.knosof.co.uk/cbook/cbook.html)
 * [Using C on the UNIX System - David A. Curry](http://www.bitsinthewind.com/about-dac/publications/using-c-on-the-unix-system)
+* [The GNU C Programming Tutorial](http://www.crasseux.com/books/ctut.pdf)
 
 
 ### C Sharp