Perhaps you should try some spelling variations:
"leyes estudios peruanoss." » "leyes estudios peruanos.", "series estudios peruanoss.", "los estudios peruanoss.", "seis estudios peruanoss."
"serie estudios urbano." » "serie estudio urbano.", "serie estudios peruanos.", "serie estudios hispano."
"leyes estudios urbanos." » "leyes estudio urbanos.", "leyes estudios peruanoss.", "leyes estudios hispanos.", "series estudios urbanos.", "los estudios urbanos.", "seis estudios 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 estudios urbano.") or ((("leyes estudios urbanos.") OR ("leyes estudios peruanoss."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("serie estudios urbano.") OR ((("leyes estudios urbanos.") OR ("leyes estudios peruanoss."))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"serie estudios urbano.\") or (((\"leyes estudios urbanos.\") OR (\"leyes estudios peruanoss.\"))))*".
• Removing quotes may allow a broader search: (( serie estudios urbano. ) or ((( leyes estudios urbanos. ) OR ( leyes estudios peruanoss. ))))*.