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