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: (("modified multiobjective optimization algorithm") OR ("machines using search algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified multiobjective optimization algorithm\") OR (\"machines using search algorithm\"))".
• Removing quotes may allow a broader search: (( modified multiobjective optimization algorithm ) OR ( machines using search algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective optimization algorithm") OR ("machines using search algorithm"))*.