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