Perhaps you should try some spelling variations:
"complementaridade constrained problemas" » "complementaridade contained problemas" (Expand Search)
"complementarity constraints problemaaasa" » "complementar constraints problemaaasa" (Expand Search), "complementarity constraints problematica" (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 problemas") OR ("complementarity constraints problemaaasa"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"complementaridade constrained problemas\") OR (\"complementarity constraints problemaaasa\"))".
• Removing quotes may allow a broader search: (( complementaridade constrained problemas ) OR ( complementarity constraints problemaaasa )).
• Adding a wildcard symbol may retrieve word variants: (("complementaridade constrained problemas") OR ("complementarity constraints problemaaasa"))*.