Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithm" » "modified multiobjective optimization algorithm"
"modified passive estimation algorithmssss" » "modified passive estimation algorithms", "modified pose estimation algorithmssss", "modified adaptive estimation algorithmssss"

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