Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithms"
"modified channel estimation algorithm" » "modified channel excitation algorithm"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified channel estimation algorithm") OR ("modified multiobjective optimization algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified channel estimation algorithm\") OR (\"modified multiobjective optimization algorithm\"))".
• Removing quotes may allow a broader search: (( modified channel estimation algorithm ) OR ( modified multiobjective optimization algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified channel estimation algorithm") OR ("modified multiobjective optimization algorithm"))*.