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