Perhaps you should try some spelling variations:
"complementar constrained problemassssaticos" » "complementar contained problemassssaticos" (Expand Search), "complementar constrained problemasssssaticos" (Expand Search)
"complementaridade constraints problema" » "complementaridade constraints problemas" (Expand Search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("complementar constrained problemassssaticos") OR ("complementaridade constraints problema"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"complementar constrained problemassssaticos\") OR (\"complementaridade constraints problema\"))*".
• Removing quotes may allow a broader search: (( complementar constrained problemassssaticos ) OR ( complementaridade constraints problema ))*.