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