Perhaps you should try some spelling variations:
"modified multiobjective optimized algorithm" » "modified multiobjective optimization algorithm", "modified multiobjective optimized algorithms", "modified multiobjective optimizer algorithms"
"certified network approximation algorithm" » "certified network approximation algorithms", "verified network approximation algorithm"

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: (("certified network approximation algorithm") OR ("modified multiobjective optimized algorithm"))~.
• Removing quotes may allow a broader search: (( certified network approximation algorithm ) or ( modified multiobjective optimized algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("certified network approximation algorithm") or ("modified multiobjective optimized algorithm"))*.