Perhaps you should try some spelling variations:
"modified risk optimization algorithms" » "modified risk optimisation algorithm", "modified risk estimation algorithms", "modified risk estimation algorithm", "modified robust optimization algorithms", "modified _ optimization algorithms", "modified game optimization algorithms", "modified bi1 optimization algorithms"
"modified objective predation algorithm" » "modified objective allocation algorithm", "modified objective predators algorithm", "modified objective estimation 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 risk optimization algorithms") or ("modified objective predation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified risk optimization algorithms") OR ("modified objective predation algorithm")).
• Removing quotes may allow a broader search: (( modified risk optimization algorithms ) or ( modified objective predation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified risk optimization algorithms") or ("modified objective predation algorithm"))*.