Perhaps you should try some spelling variations:
"complementaridade constrained problema" » "complementaridade contained problema" (Expand Search), "complementaridade constrained problemas" (Expand Search)
"complementar constraints problemasasasass" » "complementar constraints problemassasasass" (Expand Search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("complementaridade constrained problema") OR ("complementar constraints problemasasasass"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"complementaridade constrained problema\") OR (\"complementar constraints problemasasasass\"))*".
• Removing quotes may allow a broader search: (( complementaridade constrained problema ) OR ( complementar constraints problemasasasass ))*.