Perhaps you should try some spelling variations:
"modified response approximation algorithms" » "modified one approximation algorithms", "modified response association algorithms"
"modified objective estimation algorithm" » "modified objective optimization algorithm", "modified objective allocation algorithm"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified objective estimation algorithm") OR ("modified response approximation algorithms"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified objective estimation algorithm\") OR (\"modified response approximation algorithms\"))".
• Removing quotes may allow a broader search: (( modified objective estimation algorithm ) OR ( modified response approximation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified objective estimation algorithm") OR ("modified response approximation algorithms"))*.