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