Perhaps you should try some spelling variations:
de investigation » 13 investigating (Expand Search), 6 investigating (Expand Search)
instituto de » institute _ (Expand Search)
de mexico » new mexico (Expand Search)
universidad » universitat (Expand Search)
nacional » national (Expand Search)
autonoma » autonomy (Expand Search)
historicas, » historical, (Expand Search), histories, (Expand Search), historia, (Expand Search)

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: universidad nacional autonoma de mexico, instituto de investigation historicas,~.
• Adding a wildcard symbol may retrieve word variants: universidad nacional autonoma de mexico, instituto de investigation historicas,*.