Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithm"
"machines using pre algorithm" » "machinery using pre algorithm", "machines using mppt algorithm", "machines using qspr algorithm", "machines using _ algorithm", "machines nursing pre algorithm", "machines using one algorithm", "machines using ph 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 ("machines using pre algorithm"))~.
• Removing quotes may allow a broader search: (( modified multiobjective optimization algorithm ) or ( machines using pre algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective optimization algorithm") or ("machines using pre algorithm"))*.