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", "designed network approximation algorithm"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"defined network approximation algorithm\") OR (\"modified multiobjective estimation algorithms\"))~".
• Removing quotes may allow a broader search: (( defined network approximation algorithm ) OR ( modified multiobjective estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("defined network approximation algorithm") OR ("modified multiobjective estimation algorithms"))*.