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