Perhaps you should try some spelling variations:
"modified df estimation algorithmsss" » "modified df estimation algorithms", "modified df estimation algorithm", "modified _ estimation algorithmsss", "modified adam estimation algorithmsss", "modified bi1 estimation algorithmsss"
"modified objective optimization algorithm" » "modified multiobjective optimization algorithm", "modified objective optimization algorithms", "modified objective optimisation algorithm", "modified objective estimation algorithm"

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 df estimation algorithmsss") OR ("modified objective optimization algorithm"))~.
• Removing quotes may allow a broader search: (( modified df estimation algorithmsss ) or ( modified objective optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified df estimation algorithmsss") or ("modified objective optimization algorithm"))*.