Perhaps you should try some spelling variations:
"modified objective optimization algorithm" » "modified multiobjective optimization algorithm", "modified objective optimization algorithms", "modified objective optimisation algorithm", "modified objective estimation algorithm"
"modified df evolutionary algorithm" » "modified df evolution algorithm", "modified df solution algorithm", "modified _ evolutionary algorithm", "modified adam evolutionary algorithm", "modified bi1 evolutionary 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 objective optimization algorithm") OR ("modified df evolutionary algorithm"))~.
• Removing quotes may allow a broader search: (( modified objective optimization algorithm ) or ( modified df evolutionary algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified objective optimization algorithm") or ("modified df evolutionary algorithm"))*.