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 search algorithm" » "machines using source algorithm", "machinery using search algorithm", "machines using egarch algorithm", "machines nursing research algorithm", "machines using servo algorithm"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("machines using search algorithm") or ("modified multiobjective optimization algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("machines using search algorithm") OR ("modified multiobjective optimization algorithm")).
• Removing quotes may allow a broader search: (( machines using search algorithm ) or ( modified multiobjective optimization algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("machines using search algorithm") or ("modified multiobjective optimization algorithm"))*.