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