Perhaps you should try some spelling variations:
"defined network approximation algorithm" » "defined network approximation algorithms", "designed network approximation algorithm"
"modified adaptive quantization algorithm" » "modified adaptive estimation algorithm", "modified adaptive ventilation algorithm", "modified passive quantization 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: (("defined network approximation algorithm") OR ("modified adaptive quantization algorithm"))~.
• Removing quotes may allow a broader search: (( defined network approximation algorithm ) or ( modified adaptive quantization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("defined network approximation algorithm") or ("modified adaptive quantization algorithm"))*.