Perhaps you should try some spelling variations:
"policy optimization algorithm" » "policy optimization algorithms", "policy optimisation algorithm", "policy estimation algorithms", "topology optimization algorithm"
"a simulation algorithm" » "a solution algorithm", "a optimisation algorithm", "a estimation algorithms", "_ 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 optimization algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("a simulation algorithm") OR ("a estimation algorithm"))) OR ("policy optimization algorithm")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"a simulation algorithm\") OR (\"a estimation algorithm\"))) or (\"policy optimization algorithm\"))".
• Removing quotes may allow a broader search: (((( a simulation algorithm ) OR ( a estimation algorithm ))) or ( policy optimization algorithm )).
• Adding a wildcard symbol may retrieve word variants: (((("a simulation algorithm") OR ("a estimation algorithm"))) or ("policy optimization algorithm"))*.