Perhaps you should try some spelling variations:
"modified response approximation algorithm" » "modified response approximation algorithms", "modified one approximation algorithm", "modified response association algorithm"
"modified network estimation algorithm" » "modified network optimization algorithm", "certified network estimation algorithm", "defined network estimation algorithm", "modified near estimation algorithm"

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 response approximation algorithm") OR ("modified network estimation algorithm"))~.
• Removing quotes may allow a broader search: (( modified response approximation algorithm ) or ( modified network estimation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified response approximation algorithm") or ("modified network estimation algorithm"))*.