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

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