Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithms" » "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithms", "modified multiobjective estimation algorithm"
"machines using force algorithm" » "machines using source algorithm", "machines using search algorithm", "machinery using force algorithm", "machines using morse algorithm", "machines cutting force 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 algorithms") OR ("machines using force algorithm"))~.
• Removing quotes may allow a broader search: (( modified multiobjective optimization algorithms ) or ( machines using force algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective optimization algorithms") or ("machines using force algorithm"))*.