software manuals to learn open source Ubuntu Linux

software manuals to learn open source Ubuntu Linux

I bring Linux 7 books removed from www.codigolibre.org , all on 1 link.
They are very useful to get into free software and highly recommended.
The books are:

- GNU Easy

link: http://www.gigasize.com/get.php/3199446439/gnu-facil.pdf

- GNU Basic (RECOMENDADO!!)

link: http://www.gigasize.com/get.php/3199446437/GNU-Basico.pdf

- Security of GNU / Linux

link: http://www.gigasize.com/get.php/3199446441/Seguridad-GNU-Final.pdf

- Network Administration GNU / Linux

link: http://www.gigasize.com/get.php/3199446440/networking.pdf

- Administration of GNU / Linux

link: http://www.gigasize.com/get.php/3199446435/Administracion-GNU-Final.pdf

- Basics of GNU / Linux

link: http://www.gigasize.com/get.php/3199446436/Fundamentos-Final-X.pdf

- GNU Basically (Second Edition)

link: http://www.gigasize.com/get.php/3199446438/GNU-Ejercicios-FINAL.pdf

I hope you learn! Greetings