Perhaps you should try some spelling variations:
"modified passive optimisation algorithm" » "modified passive optimization algorithms", "modified passive estimation algorithm", "modified passive estimation algorithms", "modified adaptive optimisation algorithm"
"modified bayesian estimation algorithmss" » "modified bayesian estimation algorithms", "modified bayesian estimation algorithm", "modified bayesian optimization algorithms", "modified bayesian optimization algorithmss"

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 passive optimisation algorithm") or ("modified bayesian estimation algorithmss"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified passive optimisation algorithm") OR ("modified bayesian estimation algorithmss")).
• Removing quotes may allow a broader search: (( modified passive optimisation algorithm ) or ( modified bayesian estimation algorithmss )).
• Adding a wildcard symbol may retrieve word variants: (("modified passive optimisation algorithm") or ("modified bayesian estimation algorithmss"))*.