Perhaps you should try some spelling variations:
"modified optimal estimation algorithms" » "modified optimal estimation algorithm", "modified optimal optimization algorithms", "modified optimal optimisation algorithm", "modified optimal taxation algorithms", "modified thermal estimation algorithms"
"modified objective predation algorithm" » "modified objective allocation algorithm", "modified objective predators algorithm", "modified objective estimation 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 optimal estimation algorithms") OR ("modified objective predation algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified optimal estimation algorithms\") OR (\"modified objective predation algorithm\"))".
• Removing quotes may allow a broader search: (( modified optimal estimation algorithms ) OR ( modified objective predation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified optimal estimation algorithms") OR ("modified objective predation algorithm"))*.