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