Hi nadieshda,

let me check what you are wanting to do:

1 - Joomla Home page (standard "frontpage" articles view?): template "libreriainternacional"

2 - "eventos especiales" page: using normal Joomla template assignment: template "LIcomponent"

3 - "Libros" section. This is identified by the "Section_id=7" at the end of the URL. For this page you want a different template.

4 - I am not sure if you intend the template for this entry URL to be "sticky". If you're following the "Switch template according to entry URL" video, then this suggests that you want the new template remembered even after the user has navigated away from the "Section_id=7" page.
However, this sounds a bit unlikely.
Can you please explain exactly what you want to happen here? I wonder if you want the new template to be displayed just on certain pages within "Section_id=7". But how do you intend to identify when the user is on those particular pages, and how can you tell when they have left these pages and gone back to a page on the rest of the site?
Is there something special about all the books in the "Section_id=7" section? e.g. from the same VM "manufacturer", or in certain VM categories, etc? If so, you can use those attributes to use the new template just for these items.

Sorry I can't give a "howto" just yet, as I don't quite understand what you're wanting.

Best regards,
Stephen