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