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