Perhaps you should try some spelling variations:
"modified objective estimation algorithms" » "modified objective estimation algorithm", "modified objective optimization algorithms", "modified objective optimisation algorithm", "modified objective allocation algorithms"
"verified network approximation algorithms" » "certified network approximation algorithms", "defined network 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: (("verified network approximation algorithms") OR ("modified objective estimation algorithms"))~.
• Removing quotes may allow a broader search: (( verified network approximation algorithms ) or ( modified objective estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("verified network approximation algorithms") or ("modified objective estimation algorithms"))*.