Perhaps you should try some spelling variations:
"modified one approximation algorithms" » "modified time approximation algorithms", "modified _ approximation algorithms", "modified rough approximations algorithms", "modified male approximation algorithms", "modified near approximation algorithms", "modified orca approximation algorithms"
"mapping learning methods algorithm" » "machine learning methods algorithm", "enabling learning methods algorithm", "mapping nursing 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 one approximation algorithms") OR ("mapping learning methods algorithm"))~.
• Removing quotes may allow a broader search: (( modified one approximation algorithms ) or ( mapping learning methods algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified one approximation algorithms") or ("mapping learning methods algorithm"))*.