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

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

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