The Benson Latin American Collection and LLILAS host or have lots of research resources on line that might be relevant to your topics.
TIPS:
You can use the Library Catalog's drop down menus to only display content in Spanish.
http://www.kb.dk/permalink/2006/poma/titlepage/es/text/?open=idp23904
UT's LANIC site is also a good source for readily available information on the web.