Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithms" » "modified multiobjective optimization algorithms", "modified multiobjective estimation algorithm", "modified multiobjective optimisation algorithm"
"modified total approximation algorithms" » "modified one approximation algorithms", "modified time approximation algorithms", "modified rough approximations algorithms", "modified thermal approximation algorithms", "modified ti6al4v approximation 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 multiobjective estimation algorithms") OR ("modified total approximation algorithms"))~.
• Removing quotes may allow a broader search: (( modified multiobjective estimation algorithms ) or ( modified total approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective estimation algorithms") or ("modified total approximation algorithms"))*.