If you are planning to use this in your classes...

You´re most welcome to do so, and a I do feel honored. I encourage you to use it following the fair use guidelines as provided in the following article of Insider Higher Ed.:
However, I would like to do provide with some information about the blog you are reading:
The material you are reading was registered in its entirety at the Spanish Registry of Intelectual Property on 08/03/2009. This means that all rights are reserved.
The blog is also listed on Digital CSIC the Open Access Public Repository of the Consejo Superior of Investigaciones Científicas (CSIC), a public sponsored scientific institution of the Government of Spain. Since it´s the current institution I´m currently working for, undue usage is liable to institutional notice.