Perhaps you should try some spelling variations:
"modified adam approximation algorithm" » "modified adam approximation algorithms", "modified _ approximation algorithm", "modified one approximation algorithm", "modified time approximation algorithm", "modified df approximation algorithm", "modified near approximation algorithm"
"modified learning evolutionary algorithm" » "modified learning evolution algorithm", "modified learning solution algorithm", "mobile learning evolutionary algorithm", "modified caging evolutionary 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 evolutionary algorithm") or ("modified adam approximation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified learning evolutionary algorithm") OR ("modified adam approximation algorithm")).
• Removing quotes may allow a broader search: (( modified learning evolutionary algorithm ) or ( modified adam approximation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified learning evolutionary algorithm") or ("modified adam approximation algorithm"))*.