Perhaps you should try some spelling variations:
"machines learning methods algorithm" » "machine learning methods algorithm", "active learning methods algorithm", "mapping learning methods algorithm", "machines nursing methods algorithm"
"modified df approximation algorithms" » "modified _ approximation algorithms", "modified one approximation algorithms", "modified time approximation algorithms", "modified adam approximation algorithms", "modified bi1 approximation algorithms"

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: (("machines learning methods algorithm") OR ("modified df approximation algorithms"))~.
• Removing quotes may allow a broader search: (( machines learning methods algorithm ) or ( modified df approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("machines learning methods algorithm") or ("modified df approximation algorithms"))*.