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