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