Perhaps you should try some spelling variations:
"modified response optimization algorithms" » "modified response optimisation algorithm", "modified response estimation algorithms", "modified response estimation 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 response optimization algorithms"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified notion approximation algorithms\") OR (\"modified response optimization algorithms\"))*".
• Removing quotes may allow a broader search: (( modified notion approximation algorithms ) OR ( modified response optimization algorithms ))*.