Perhaps you should try some spelling variations:
"complementaridade constrained problem" » "complementaridade contained problem" (Expand Search), "complementaridade constrained problema" (Expand Search), "complementaridade constrained problemas" (Expand Search)
"complementar constraints problematic" » "complementar constraints problemaatic" (Expand Search), "complementar constraints problemasatic" (Expand Search), "complementar 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 problem") OR ("complementar constraints problematic"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"complementaridade constrained problem\") OR (\"complementar constraints problematic\"))*".
• Removing quotes may allow a broader search: (( complementaridade constrained problem ) OR ( complementar constraints problematic ))*.