Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithms" » "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithms", "modified multiobjective estimation algorithm"
"modified oxygen evolution algorithm" » "modified oxygen solution algorithm", "modified oxygen evolutionary algorithm", "modified oxygen convolution algorithms"

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 oxygen evolution algorithm") OR ("modified multiobjective optimization algorithms"))~.
• Removing quotes may allow a broader search: (( modified oxygen evolution algorithm ) or ( modified multiobjective optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified oxygen evolution algorithm") or ("modified multiobjective optimization algorithms"))*.