Perhaps you should try some spelling variations:
"complementarity constraints problem" » "complementaridade constraints problem" (Expand Search), "complementarity constraints problema" (Expand Search), "complementarity constraints problemas" (Expand Search)
"complementar obtained problemaasasaaass" » "complementar obtained problemaaasasaaass" (Expand Search), "complementar obtained problemasaasasaaass" (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 obtained problemaasasaaass") OR ("complementarity constraints problem"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"complementar obtained problemaasasaaass\") OR (\"complementarity constraints problem\"))".
• Removing quotes may allow a broader search: (( complementar obtained problemaasasaaass ) OR ( complementarity constraints problem )).
• Adding a wildcard symbol may retrieve word variants: (("complementar obtained problemaasasaaass") OR ("complementarity constraints problem"))*.