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