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