[TYPO3-english] Translating search content type

[Francesc Juliana]

Hello:
I am building a website. One page contains one search type content element.
I would like to translate the search content type strings but I don't know 
if it's a system extension.
I have supposed that it was indexed_serach but I haven't found strings that 
appear on page.
Anyone knows which is the extension or lib that I must translate for search 
content element?

Thanks in advance.

Francesc