Perhaps you should try some spelling variations:
"modified parameter estimation algorithm" » "modified parameter estimates algorithm", "modified parameter optimization 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.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified parameter estimation algorithm") or ("modified df approximation algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified parameter estimation algorithm") OR ("modified df approximation algorithms"))*.
• Removing quotes may allow a broader search: (( modified parameter estimation algorithm ) or ( modified df approximation algorithms ))*.