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