Need Help On Old Newspapers (Colonial Times)

La Gaceta was one of the newspapers that was in circulation since 1722 in Mexico and I had gone to a website of the UNAM where you just enter what you want to look for in basic search. For example, "Fernando De La Campa y Cos" and it would list all newspapers along with years that has articles highlighted in yellow containing the words "Fernando De La Campa." I was quickly able to read old articles going as far back as 1722.

But it seems the UNAM changed their website:

http://www.hndm.unam.mx/index.php/es/

Now when I try to search for "Fernando De La Campa" It doesn't look for the exact words even if I go to advanced search. Also now many of those articles are:

"Restringido (PDF)" means you can only look at them from within the institution.

"Publico" means you can view them on the internet.

I can't find Fernando De La Campa like before they changed their website.

Do any of you know of other websites to look at old newspaper articles during colonial times?