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