Perhaps you should try some spelling variations:
"modified bi1 optimization algorithm" » "modified bi1 optimization algorithms", "modified bi1 optimisation algorithm", "modified bi1 estimation algorithms", "modified _ optimization algorithm", "modified qoe optimization algorithm", "modified game optimization algorithm"
"modified parameters estimation algorithm" » "modified parameter estimation algorithm", "modified parameter estimates algorithm", "modified parameter optimization algorithm"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified bi1 optimization algorithm") or ("modified parameters estimation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified bi1 optimization algorithm") OR ("modified parameters estimation algorithm")).
• Removing quotes may allow a broader search: (( modified bi1 optimization algorithm ) or ( modified parameters estimation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified bi1 optimization algorithm") or ("modified parameters estimation algorithm"))*.