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