Perhaps you should try some spelling variations:
"modified multiobjective approximation algorithms" » "modified multiobjective optimization algorithms"
"modified make estimation algorithms" » "modified make estimation algorithm", "modified make optimization algorithms", "modified make optimisation algorithm", "modified pose estimation algorithms", "modified male estimation 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 multiobjective approximation algorithms") OR ("modified make estimation algorithms"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified multiobjective approximation algorithms\") OR (\"modified make estimation algorithms\"))".
• Removing quotes may allow a broader search: (( modified multiobjective approximation algorithms ) OR ( modified make estimation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective approximation algorithms") OR ("modified make estimation algorithms"))*.