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