Perhaps you should try some spelling variations:
"modified notion approximation algorithms" » "modified network approximation algorithms", "modified time approximation algorithms", "modified one approximation algorithms"
"mapping learning method algorithm" » "machine learning method algorithm", "enabling learning method algorithm", "mapping learning mom algorithm", "mapping learning methods algorithm", "mapping graining methods algorithm", "mapping learning emotion algorithm"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("mapping learning method algorithm") or ("modified notion approximation algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("mapping learning method algorithm") OR ("modified notion approximation algorithms")).
• Removing quotes may allow a broader search: (( mapping learning method algorithm ) or ( modified notion approximation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("mapping learning method algorithm") or ("modified notion approximation algorithms"))*.