Perhaps you should try some spelling variations:
"modified bi1 approximation algorithm" » "modified bi1 approximation algorithms", "modified time approximation algorithm", "modified _ approximation algorithm", "modified one approximation algorithm"
"modified notion estimation algorithms" » "modified notion estimation algorithm", "modified notion optimization algorithms", "modified notion optimisation algorithm", "modified motion estimation 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 bi1 approximation algorithm"))~.
• Removing quotes may allow a broader search: (( modified notion estimation algorithms ) or ( modified bi1 approximation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified notion estimation algorithms") or ("modified bi1 approximation algorithm"))*.