Perhaps you should try some spelling variations:
"modified passive optimization algorithms" » "modified passive optimisation algorithm", "modified passive estimation algorithms", "modified passive estimation algorithm", "modified bayesian optimization algorithms", "modified game optimization algorithms", "modified policy optimization algorithms", "modified adaptive optimization algorithms"
"modified df predators algorithm" » "modified df predation algorithm", "modified _ predators algorithm", "modified adam predators algorithm", "modified bi1 predators algorithm"

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