Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithm" » "modified multiobjective optimization algorithm"
"modified passive optimized algorithms" » "modified passive optimized algorithm", "modified passive optimizer algorithms", "modified passive optimization algorithms", "modified adaptive optimized 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 passive optimized algorithms") OR ("modified multiobjective estimation algorithm"))~.
• Removing quotes may allow a broader search: (( modified passive optimized algorithms ) or ( modified multiobjective estimation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified passive optimized algorithms") or ("modified multiobjective estimation algorithm"))*.