Perhaps you should try some spelling variations:
"modified passive quantization algorithm" » "modified passive estimation algorithm", "modified adaptive quantization algorithm"
"modified notion approximation algorithms" » "modified network approximation algorithms", "modified time approximation algorithms", "modified one approximation algorithms"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified notion approximation algorithms") or ("modified passive quantization algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified notion approximation algorithms") OR ("modified passive quantization algorithm")).
• Removing quotes may allow a broader search: (( modified notion approximation algorithms ) or ( modified passive quantization algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified notion approximation algorithms") or ("modified passive quantization algorithm"))*.