Perhaps you should try some spelling variations:
"modified objective optimization algorithms" » "modified objective optimisation algorithm", "modified objective estimation algorithms", "modified objective estimation algorithm", "modified multiobjective optimization algorithms"
"modified graph evolutionary algorithm" » "modified graph evolution algorithm", "modified graph solution algorithm"

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 graph evolutionary algorithm\") OR (\"modified objective optimization algorithms\"))~".
• Removing quotes may allow a broader search: (( modified graph evolutionary algorithm ) OR ( modified objective optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified graph evolutionary algorithm") OR ("modified objective optimization algorithms"))*.