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