Perhaps you should try some spelling variations:
"policy estimation algorithms" » "policy optimization algorithms", "policy optimisation algorithm", "policy approximation algorithms", "pose estimation algorithms", "motion estimation algorithms"
"_ simulation algorithm" » "_ solution algorithm", "_ optimisation algorithm", "_ evolution algorithm"
"a estimation algorithm" » "_ estimation algorithm", "a destination algorithm", "_ estimating algorithm"

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

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