Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithm"
"machine graining methods algorithm" » "machine learning methods algorithm", "machine learning method algorithm", "machine making methods 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 ("machine graining methods algorithm"))~.
• Removing quotes may allow a broader search: (( modified multiobjective optimization algorithm ) or ( machine graining methods algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective optimization algorithm") or ("machine graining methods algorithm"))*.