Perhaps you should try some spelling variations:
"serie estudios y investigacion" » "serie estudios e investigacion", "serie estudios la investigacion", "serie estudios de investigacion", "seis estudios y investigacion", "series studies y investigacion", "peru estudios y investigacion", "serie estudios en investigacion", "serie studios _ investigacion"
"sers studies y investigacion" » "sers studies e investigacion", "sers studies la investigacion", "sers studies de investigacion", "series studies y investigacion", "mrs studies y investigacion", "beams studies y investigacion", "sers studies 2 investigacion", "sers studies 1 investigacion", "sers studies 0 investigacion"

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 y investigacion") OR ("sers studies y investigacion"))*.
• Removing quotes may allow a broader search: (( serie estudios y investigacion ) or ( sers studies y investigacion ))*.