Perhaps you should try some spelling variations:
"complementarity constrained problema" » "complementar constrained problema" (Expand Search), "complementarity contained problema" (Expand Search), "complementarity constrained problemas" (Expand Search)
"complementaridade constraints problemass" » "complementaridade constraints problemasss" (Expand Search), "complementaridade constraints problemas" (Expand Search), "complementaridade constraints problems" (Expand Search), "complementaridade constraints problemes" (Expand Search)

Try widening your search to All Fields.

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

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