Perhaps you should try some spelling variations:
"serie studia americanos." » "serie estudios americanos.", "serie estados americanos.", "serie dia americano."
"serie estudio urbanos." » "serie estudio urbano.", "serie estudios urbano.", "serie estudios peruanos.", "series estudios urbanos.", "serie estado urbanos.", "serie estudos urbanos."
"serie estudios urbanos." » "series estudioss urbanos.", "serie estados urbanos.", "serie estudoss urbanos."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("serie estudio urbanos.") OR ("serie estudios urbanos."))) or ("serie studia americanos."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("serie estudio urbanos.") OR ("serie estudios urbanos."))) OR ("serie studia americanos."))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"serie estudio urbanos.\") OR (\"serie estudios urbanos.\"))) or (\"serie studia americanos.\"))*".
• Removing quotes may allow a broader search: (((( serie estudio urbanos. ) OR ( serie estudios urbanos. ))) or ( serie studia americanos. ))*.