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