Perhaps you should try some spelling variations:
"modified df estimation algorithmssssss" » "modified df estimation algorithms", "modified df estimation algorithm", "modified _ estimation algorithmssssss", "modified adam estimation algorithmssssss", "modified bi1 estimation algorithmssssss"
"modified objective optimisation algorithm" » "modified objective optimization algorithm", "modified multiobjective optimization algorithm", "modified objective optimization algorithms", "modified objective estimation algorithm", "modified objective estimation 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 df estimation algorithmssssss") or ("modified objective optimisation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified df estimation algorithmssssss") OR ("modified objective optimisation algorithm")).
• Removing quotes may allow a broader search: (( modified df estimation algorithmssssss ) or ( modified objective optimisation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified df estimation algorithmssssss") or ("modified objective optimisation algorithm"))*.