Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithms" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective approximation algorithms"
"active learning estimation algorithm" » "active learning emotion algorithm", "active lighting estimation algorithm", "machine learning estimation 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: "((\"modified multiobjective estimation algorithms\") OR (\"active learning estimation algorithm\"))~".
• Removing quotes may allow a broader search: (( modified multiobjective estimation algorithms ) OR ( active learning estimation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective estimation algorithms") OR ("active learning estimation algorithm"))*.