Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithm" » "modified multiobjective optimization algorithm"
"modified large approximation algorithms" » "modified average approximation algorithms", "modified one approximation algorithms", "modified time approximation algorithms", "modified male approximation algorithms"

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: (("modified large approximation algorithms") or ("modified multiobjective estimation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified large approximation algorithms") OR ("modified multiobjective estimation algorithm")).
• Removing quotes may allow a broader search: (( modified large approximation algorithms ) or ( modified multiobjective estimation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified large approximation algorithms") or ("modified multiobjective estimation algorithm"))*.