Perhaps you should try some spelling variations:
"multi-objective optimization solving ii" » "multi-objective optimization self ii", "multi-objective optimization solving ill", "multi-objective optimization solving its", "multi-objective optimization solving iccp"
"multi-objective optimization sql ii" » "multi-objective optimization self ii", "multi-objective optimization seo ii", "multi-objective optimization set ii", "multi-objective optimization sql iii", "multi-objective optimization sql im", "multi-objective optimization sql 9i"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("multi-objective optimization sql ii") OR ("multi-objective optimization solving ii")).
• Removing quotes may allow a broader search: (( multi-objective optimization sql ii ) or ( multi-objective optimization solving ii )).
• Adding a wildcard symbol may retrieve word variants: (("multi-objective optimization sql ii") or ("multi-objective optimization solving ii"))*.