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