Perhaps you should try some spelling variations:
"modified objective optimization algorithms" » "modified objective optimisation algorithm", "modified objective estimation algorithms", "modified objective estimation algorithm", "modified multiobjective optimization algorithms"
"modified nacl approximation algorithms" » "modified _ approximation algorithms", "modified one approximation algorithms", "modified time approximation algorithms", "modified male approximation algorithms", "modified near approximation algorithms", "modified orca 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 nacl approximation algorithms") OR ("modified objective optimization algorithms"))~.
• Removing quotes may allow a broader search: (( modified nacl approximation algorithms ) or ( modified objective optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified nacl approximation algorithms") or ("modified objective optimization algorithms"))*.