Perhaps you should try some spelling variations:
"complementarity constraints problem" » "complementar constraints problem" (Expand Search), "complementaridade constraints problem" (Expand Search), "complementarity constraints problema" (Expand Search), "complementarity constraints problemas" (Expand Search)
"Complementarity obtained problemass" » "Complementarity obtained problemas" (Expand Search), "Complementarity obtained problema" (Expand Search), "Complementarity obtained problems" (Expand Search), "Complementarity obtained problemaass" (Expand Search), "Complementarity obtained problemasass" (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("Complementarity obtained problemass") OR ("complementarity constraints problem"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"Complementarity obtained problemass\") OR (\"complementarity constraints problem\"))".
• Removing quotes may allow a broader search: (( Complementarity obtained problemass ) OR ( complementarity constraints problem )).
• Adding a wildcard symbol may retrieve word variants: (("Complementarity obtained problemass") OR ("complementarity constraints problem"))*.