Perhaps you should try some spelling variations:
"modified _ optimization algorithms" » "modified _ optimisation algorithm", "modified _ estimation algorithms", "modified _ estimation algorithm", "modified _ optimisation algorithms", "modified _ estimation algorithmss"
"modified objective optimization algorithm" » "modified multiobjective optimization algorithm", "modified objective optimisation algorithm", "modified objective estimation algorithm", "modified objective estimation algorithms"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified objective optimization algorithm\") OR (\"modified _ optimization algorithms\"))~".
• Removing quotes may allow a broader search: (( modified objective optimization algorithm ) OR ( modified _ optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified objective optimization algorithm") OR ("modified _ optimization algorithms"))*.