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