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