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