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