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