Perhaps you should try some spelling variations:
"modified multiobjective approximation algorithms" » "modified multiobjective optimization algorithms"
"mobile learning predators algorithm" » "mobile learning predation algorithm", "mobile marine predators algorithm", "machine learning predators algorithm"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified multiobjective approximation algorithms") or ("mobile learning predators algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified multiobjective approximation algorithms") OR ("mobile learning predators algorithm")).
• Removing quotes may allow a broader search: (( modified multiobjective approximation algorithms ) or ( mobile learning predators algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective approximation algorithms") or ("mobile learning predators algorithm"))*.