Perhaps you should try some spelling variations:
"defined network optimization algorithms" » "defined network optimisation algorithm", "defined network estimation algorithm", "defined network optimized algorithms"
"modified objective estimation algorithms" » "modified objective estimation algorithm", "modified objective optimisation algorithm", "modified objective approximation algorithms", "modified objective optimization algorithms", "modified objective allocation algorithms"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified objective estimation algorithms") OR ("defined network optimization algorithms"))~.
• Removing quotes may allow a broader search: (( modified objective estimation algorithms ) or ( defined network optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified objective estimation algorithms") or ("defined network optimization algorithms"))*.