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