Perhaps you should try some spelling variations:
"modified df approximation algorithm" » "modified df approximation algorithms", "modified _ approximation algorithm", "modified one approximation algorithm", "modified time approximation algorithm", "modified adam approximation algorithm", "modified bi1 approximation algorithm"
"modified adaptive convolution algorithms" » "modified adaptive evolution algorithm", "modified adaptive solution algorithm", "modified adaptive construction algorithms", "modified adaptive ventilation algorithms", "modified passive convolution 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: (("modified adaptive convolution algorithms") OR ("modified df approximation algorithm"))~.
• Removing quotes may allow a broader search: (( modified adaptive convolution algorithms ) or ( modified df approximation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified adaptive convolution algorithms") or ("modified df approximation algorithm"))*.