Perhaps you should try some spelling variations:
"modified response optimization algorithms" » "modified response optimisation algorithm", "modified response estimation algorithms", "modified response estimation 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: (("modified response optimization algorithms") OR ("modified df approximation algorithms"))~.
• Removing quotes may allow a broader search: (( modified response optimization algorithms ) or ( modified df approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified response optimization algorithms") or ("modified df approximation algorithms"))*.