Perhaps you should try some spelling variations:
"complementarity constrained problemas" » "complementar constrained problemas" (Expand Search), "complementarity contained problemas" (Expand Search)
"complementaridade constraints problemass" » "complementaridade constraints problema" (Expand Search), "complementaridade constraints problems" (Expand Search), "complementaridade constraints problemes" (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: "((\"complementarity constrained problemas\") OR (\"complementaridade constraints problemass\"))~".
• Removing quotes may allow a broader search: (( complementarity constrained problemas ) OR ( complementaridade constraints problemass ))~.
• Adding a wildcard symbol may retrieve word variants: (("complementarity constrained problemas") OR ("complementaridade constraints problemass"))*.