Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithms" » "modified multiobjective optimization algorithms", "modified multiobjective estimation algorithm", "modified multiobjective optimisation algorithm"
"modified orca approximation algorithms" » "modified one approximation algorithms", "modified _ approximation algorithms", "modified time approximation algorithms"

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: (("modified multiobjective estimation algorithms") OR ("modified orca approximation algorithms"))~.
• Removing quotes may allow a broader search: (( modified multiobjective estimation algorithms ) or ( modified orca approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective estimation algorithms") or ("modified orca approximation algorithms"))*.