Perhaps you should try some spelling variations:
"serie estudios e investigaciones" » "serve estudios e investigaciones", "serie studio e investigaciones", "serie estudios e investigations", "serie estudios e investigation", "serie studios e investigaciones", "serie estudios e investigationes", "serie estudios e investigationses", "serie estudios e investigatinges"
"serie estudio la investigacion" » "serve estudio la investigacion", "serie studio la investigacion", "serie estudio la investigation", "serie estudio la investigations", "serie estudio la investigating"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("serie estudios e investigaciones") OR ("serie estudio la investigacion")).
• Removing quotes may allow a broader search: (( serie estudios e investigaciones ) or ( serie estudio la investigacion )).
• Adding a wildcard symbol may retrieve word variants: (("serie estudios e investigaciones") or ("serie estudio la investigacion"))*.