Perhaps you should try some spelling variations:
"modified _ optimization algorithms" » "modified _ optimisation algorithm", "modified _ estimation algorithms", "modified _ estimation algorithm"
"modified positive evolutionary algorithm" » "modified positive evolution algorithm", "modified positive solution algorithm", "modified objective evolutionary algorithm", "modified positive solutions algorithm", "modified passive evolutionary algorithm", "modified adaptive evolutionary algorithm"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified positive evolutionary algorithm") OR ("modified _ optimization algorithms"))~.
• Removing quotes may allow a broader search: (( modified positive evolutionary algorithm ) or ( modified _ optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified positive evolutionary algorithm") or ("modified _ optimization algorithms"))*.