Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithm"
"modified optimal solution algorithm" » "modified optimal evolution algorithm", "modified optimal convolution algorithms", "modified optimal evolutionary algorithm", "modified thermal solution 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 optimal solution algorithm") OR ("modified multiobjective optimization algorithm"))~.
• Removing quotes may allow a broader search: (( modified optimal solution algorithm ) or ( modified multiobjective optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified optimal solution algorithm") or ("modified multiobjective optimization algorithm"))*.