Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithms"
"modified risk estimation algorithm" » "modified pose estimation algorithm", "modified bi1 estimation 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 multiobjective optimization algorithm") OR ("modified risk estimation algorithm"))~.
• Removing quotes may allow a broader search: (( modified multiobjective optimization algorithm ) or ( modified risk estimation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective optimization algorithm") or ("modified risk estimation algorithm"))*.