Perhaps you should try some spelling variations:
"modified df estimation algorithms" » "modified df optimization algorithms", "modified df optimisation algorithm", "modified df approximation algorithms", "modified _ estimation algorithms", "modified adam estimation algorithms", "modified bi1 estimation algorithms"
"modified adaptive estimation algorithm" » "modified adaptive ventilation algorithm", "modified quantile estimation algorithm", "modified adaptive quantization algorithm", "modified passive estimation algorithm"

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 estimation algorithm") OR ("modified df estimation algorithms"))~.
• Removing quotes may allow a broader search: (( modified adaptive estimation algorithm ) or ( modified df estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified adaptive estimation algorithm") or ("modified df estimation algorithms"))*.