Perhaps you should try some spelling variations:
"luca una investigacion" » "luca la investigacion", "luca e investigacion", "luca ciencia investigacion", "luca unla investigacion", "luca une investigacion", "luca unen investigacion", "lucha una investigacion", "luca un investigacion", "lucas unas investigacion"
"juan de investigacion" » "juan la investigacion"
"lucan a investigacion" » "lucan la investigacion", "lucan e investigacion", "lucan en investigacion", "lucan ma investigacion", "lucas la investigacion"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("lucan a investigacion") or ("luca una investigacion"))) or ("juan de investigacion"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("lucan a investigacion") OR ("luca una investigacion"))) OR ("juan de investigacion")).
• Removing quotes may allow a broader search: (((( lucan a investigacion ) or ( luca una investigacion ))) or ( juan de investigacion )).
• Adding a wildcard symbol may retrieve word variants: (((("lucan a investigacion") or ("luca una investigacion"))) or ("juan de investigacion"))*.